The biological study of animals.

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Why do men have nipples?

I'd be tempted to call nipples in men vestigial, but that suggests they have no modern function. They do have a function, of course, but only in women. So why do men (and all male mammals) have them?
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1answer
2k views

Do fish break a water molecule to absorb oxygen?

How do fish separate oxygen from H20 & consume it? Do they break the water molecule and absorb the oxygen only?
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3answers
85 views

ID flying insect found in Belgium

I live in Belgium, and I've just witnessed a weird looking wasp/fly flying around in my room. Here's a picture: So, what's this? It's still in my room, just chilling there. It zooms like a wasp, ...
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1answer
121 views

How much do crocodiles eat?

How much do crocodiles eat? The closest I found to an answer was on German wikipedia, where it says that adult nile crocodiles eat "only about 50 full meals a year." While interesting, without knowing ...
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0answers
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Venom Denaturing with Heat

My friend got stung by a stingray yesterday and the lifeguard quickly stuck her foot into hot water (she said the water burned slightly on contact) and remarkably, she was walking without pain in a ...
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2answers
42 views

Spatial dimensions for an animal

I'm reading a review paper. They say: The position of an object in head-centered coordinates (that is, relative to an animal's head) can be defined along three axes: the medio-lateral (radial) ...
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1answer
38 views

Plant cell question in age 12 science test Part II

I'm a parent and I think the teacher had been a bit harsh with marking most of these questions but can someone help me answer the very last question on the paper please (where someone has written SP ...
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1answer
67 views

Do ants use something similar to the honey bee “waggle dance” to instruct the rest of the colony where to find a food source?

In the 20 years since we built our home, we've just recently had our first ant infestation. I'm familiar with the fact that ants leave scent trails to find their way back and forth between the ...
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1answer
98 views

Is there a mechanism by which mammals lose interest in a partner after mating?

I'm reading the book called "Cupid's poison arrow", which revolves around a rather simple assumption: most mammals, including humans have a genetic program that is responsible for ever increasing ...
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1answer
39 views

Can salt-water frogs survive in normal water (A well)?

I don't know much about frogs, but there seem to be salt water frogs. 1) Are there such things as salt water frogs? 2) Are there frogs that live in the sea? (in reference to Vivekananda's quote) 3) ...
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1answer
683 views

Why don't rats have a gallbladder, unlike other rodents?

It has long been known that rats do not have a gallbladder, though other species including humans, monkeys, cows, reptiles, dogs and mice, all have a gallbladder. In this paper from almost 100 years ...
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Does increased calorie intake cause increase in libido in humans?

I'm interested in the effect of increased calorie intake on sex hormones and chosen mating strategy in humans. I'm aware that humans have a dual mating strategy - somewhere between pair bond and ...
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26 views

Is it safe to feed an adult fire salamander with slime maggots? [closed]

As a reminder, maggots feed of a flesh, while fire salamander consumes his prey alive, without killing it. Can it happen that the maggot will start eating the salamander from the inside?
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84 views

Found an unknown species, whom should I contact?

My father has found a very queer looking insect. He'd been watching it for over half a year on the tree right next to our house and in all this time hasn't been able to find anything like it on the ...
3
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2answers
727 views

What is the fastest marine mammal?

When I did a research, most of the sources say that orca is one of the fastest. But I could not find a source that says it is actually the fastest. Some sources say that Dall's porpoises rival orcas ...
3
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1answer
94 views

Identification of a spider from my basement

It's a little over 1" long including legs, and I found it in my basement in Pennsylvania. My guess is a funnel weaver, which would be nice since then I can free it (right?) from the tin can it's ...
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Could we restore some animal's muscle structure by it's bone?

Suppose that elephant dies out one day, nothing left to researchers but the fossil. Could fossil infer the existence of large nose? If there is possibility, how exactly should they perform the ...
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Can someone identify this snail? Thanks

Found in an almost dried out brook in Eastern Massachusetts. This is the lowest the brook has been in anyone's memory.
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1answer
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Can ants survive a plane ride?

I just came back home a few hours ago from the airport and my aunt had peaches in her car full of ants. This made me wonder if the ants had joined us from the plane? This leads to the question can ...
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4answers
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Why do smaller mammals move intermittently?

I was watching a nice little video on youtube but couldn't help but notice how snappy smaller animals such as rats and chipmunks move. By snappy I mean how the animal moves in almost discrete states ...
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2answers
43 views

Predator prey interaction [closed]

I went through a line in my textbook which read: "But for predators, prey species could achieve very high population densities and cause ecosystem instability." I was not able to understand the ...
3
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1answer
29 views

Could a large constrictor kill a small animal?

According to this article there was a python whose body circumference was 85cm. This means its diameter was 27cm. Would it be possible for this snake to constrict animals that are about the same ...
3
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1answer
41 views

Is there evidence to suggest that sharks from prehistoric times live in the deep of the oceans?

I've had friends see the boat and giant teeth of a giant shark attack of a boat in Japan. (Teeth larger than a great white). [I can't find anything about this on the Internet]. In addition, this ...
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0answers
32 views

Why people have less hair than other primates? [duplicate]

Well as you can figure out, most primates such as monkeys, gorillas and chimpanzees, have all their body covered with fur. As we know they are evolutional "relatives" to us humans, but we dont have ...
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Why do orcas eat only the tongue of whales, liver of sharks, etc.?

I noticed that although killer whales are clearly the top predator living in the present oceans, some of them appear to be very picky with their meals. After spending hours hunting down a whale, ...
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2answers
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Do any terrestrial herbivores use auditory crypsis for predator avoidance? [closed]

Some terrestrial predators "stalk" their prey: they sneak up on it slowly, maintaining a low profile, while keeping as close to silent as possible. This makes sense from an evolutionary perspective: ...
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1answer
146 views

Why Crocodiles don't eat Hippos?

I have been following documentaries about crocodiles and amazingly, crocodiles and hippos apparently seem to live happily in the same pond together without attacking each other. Why is it so? Like ...
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2answers
59 views

Insect making continuous sound in summers

In deciduous to tropical-deciduous forests and residential places with such vegetation I have found this insect to make continuous sounds all through the day (even in nights sometimes) during the ...
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Why do horses recycle their endometrial lining while humans don't?

How does not recycling the endometrial lining of the uterus benefit humans (and other organisms that menstruate), while recycling it is beneficial to horses (and other organisms that undergo estrus ...
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2answers
385 views

How did zootoxins evolve?

I've always wondered how toxins in certain organisms have evolved. Particularly, organisms that produce toxins as a deterrent to predators as opposed to organisms that use it to paralyze their prey. ...
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82 views

Do animals have different taste preferences within the same species?

Humans (especially children...) seem to dislike certain foods or drinks, that other humans seem to like. Common examples are coffee, french cheeses, olives, milk, fish and cabbage. Are there examples ...
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1answer
100 views

Humans genetic/phylogenetic “next relative” in central Europe? [closed]

What species in central Europe in the phylogenetic tree shows the closest difference in time to the most recent common ancestor with Homo sapiens?
13
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1answer
122 views

What made this black cluster on a leaf?

I found this black slug-shaped thing on a leaf by my pond in western Sweden. It's about 15 mm long, positioned on a vertical leaf (I bent it to take the picture). And I don't even know where to ...
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Are there any individual animals that can thrive in a wide range of core temperatures? [closed]

Surely, some cold blooded animals are in a position where they can't escape the changing temperatures the environment throws at them, so natural selection would have enabled them to thrive in a wide ...
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1answer
138 views

What were the camels' humps good for back in the polar areas?

I've heard that camels lived in the North America formerly and just in the last few thousands years they've migrated to the hot deserts. Thus they allegedly utilized the adaptations against the cold ...
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3answers
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Why are turtles classified as reptiles and not amphibians?

I understand that turtles are reptiles because like all reptiles, they have scales on their body. But turtles (specifically sea turtles) live on both land and water, very much like amphibians. Also, ...
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Why don't animals need filtered water? [duplicate]

Almost 10 years back when I was a kid, we had a picture in our school text of wild buffaloes drinking water from a river - which was visibly muddy. I asked my mother of why we need to drink filtered ...
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1answer
44 views

Is the knee locking mechanism present in animals?

We study in human anatomy that when the knee is in full extension, the femur slightly medially rotates on the tibia to lock the knee joint in place. This reduces the work required to be done by the ...
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2answers
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Can animals also get Down syndrome?

I heard that animals cannot get Down syndrome or trisomy. Is that true and why can't they get it? They also have chromosomes.
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1answer
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What is this droplet of liquid that comes out of a mosquito?

I have been looking at pictures of different species of mosquito and several times I came across pictures where the mosquito seems to be secreting some kind of fluid. In the pictures one can clearly ...
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1answer
524 views

Why do crabs spit?

Last year I photographed this juvenile Sally Lightfoot Crab (Grapsus grapsus) 'spitting' (click for larger view): I thought I'd look up more information on this behavior, but couldn't find any ...
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How much to larvae eat? (1. general and 2. specifically larvae of the bread beetle stegobium paniceum)

I'm no biologist or anything and thus the question might seem odd, but I couldn't find an answer anywhere on the web. I'm looking for information about how much larvae eat. To be exact I need to ...
6
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2answers
139 views

Which of the following lacks DNA?

a) An Enucleated ovum b) Mature RBC c) A mature spermatozoan d) Hair root According to me, there can be 2 answers, a and b because an ovum whose nucleus has been removed lacks DNA. And also, ...
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1answer
24 views

Which animal that lives in the forest makes this noise?

Which animal makes this noise? Link to audio file The file was recorded next to a forest in Germany.
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3answers
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What organs are absolutely needed by the human body?

The title is my question: what organs are absolutely needed (fatal if injured/removed) by the human body and perhaps animals in general? I'm not asking which organs are mechanically replaceable, but ...
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1answer
45 views

If crocodiles are k-selected, why do they supposedly “not age,” as in avoid senescence?

I recently saw a few sources stating that Crocodiles do not biologically age, implying negligible senescence. Basically, a 70 year old crocodile is in the same physical/health condition as a 7 year ...
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2answers
748 views

Are all quadrupeds edible? [closed]

I wonder if all quadrupeds (or, mammals, at least), are edible? From what I have collected, even down to fish, everything is edible apart from being sick or infected, and, apart from some glands ...
7
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1answer
134 views

What species of fox is this?

I found this picture of a fox in a news article about arctic foxes in Sweden (source), but I'm not sure whether it is actually an arctic fox. On the one hand, it has white fur, which is the correct ...
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2answers
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Why would a mother reject her offspring if it has been “interfered” with by humans?

There was a recent incident at Yellowstone National Park in which tourists placed a bison calf in their vehicle, and that eventually led to the calf being euthanized. The National Park Service issued ...
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Do all parasitic worms lack tango receptors on their skin?

I read that the parasitic nematodes lack tango receptors on the surface of their body. Is this true for all the parasitic worms?