The biological study of animals.

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Are tongues red because they contain blood?

Many animals have red tongues, though not all of them - blue-tongued skinks and giraffes come to mind. Are they red because of the blood (and therefore haemoglobin) in them? It sounds plausible, but ...
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Is there any reason the common housefly continues to return to an area?

This might come off as a really silly question. But I'm wondering (especially in the case of food) if there is any reason a fly would continue to try and sit on top of a piece of food even after ...
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What evolutionary mechanism caused felines to develop purring?

And why can some felines roar while others meow?
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Why do small organisms make faster movements than big organisms?

I hesitated to ask this question because it seems so obvious and intuitive. However, I am not able to explain this tendency. Background It seems to me that small organisms make faster movements than ...
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Do animals suffer from “Human” mental disorders?

It is tragic, but apparently Killer whales and Dolphins can commit suicide too (e.g. here)... This suggests they can become depressed. I wondered whether they were "clinically" depressed like many ...
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Is recognizing one's own mirror reflection a valid test of animal intelligence/self awareness?

I've been looking at this Ted talk on interspecies internet, and it appears that they have selected a small number of species of animals (dolphin, elephant, and some ape(?)) and are intent on ...
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Are there animals which can see movements better than shapes or colors?

I remember that in Michael Crichton's novel Jurassic Park, Tyrannosaurus Rex was supposed to have movement based vision. (Of course, that is a novel and not a scientific text.) I have also noticed ...
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Do all sea creatures that have scales have to have fins?

Do all sea creatures that have scales have to have fins? Do we know of any sea creatures that have only scales without fins? I'm especially interested in fish that have scales but no fins.
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Do dogs have something different about their physiology that allows them to pant without hyperventilating?

I was wondering this as I considered how effective panting would be for humans as a means of cooling.
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How do birds avoid mid-air collision?

Across from me there is a large flick of Pigeons and Ravens that like to nest on the roof. They swoop and dive and fly all over. Sometimes the whole flock lifts off at once. My question is, how do ...
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(Why) are polar bears more common in Labrador than in southern Greenland?

The Labrador Sea is between Greenland, Labrador, and Qikiqtaaluk: Map source. A Greenlandic source on polar bears states: In Greenland the polar bear lives and breeds in the northernmost parts ...
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264 views

Why are there so many sex determining systems in animals

There are several sex determining systems in animals. In mammals XY = male(except in rare cases where SRY crosses with genes on the X so that it is the reverse) and XX = female. In some birds it is ...
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Species of this White Dove

I visited a bird enclosure close to where I live in Australia. The enclosure had several different species. The birds that stood out most were these doves sitting right along the fence railing, making ...
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How do sharks and other fish conserve and gain water in marine environments?

With the osmolarity of the average vertebrate being around 300mOsml, and salt water having an osmolarity of 1000mOsml, why does the water from the shark not leave to the salt water around it? I ...
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227 views

Homologies to insect wings

All winged vertebrates have wings which are homologous to each other and to the forelimbs of the non-winged vertebrates. But what about insect wings? Are all insect wings homologous, and are there any ...
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229 views

Is there such thing as Animal non-verbal body language?

Have there been any studies done on the animal use of their bodies to signal, communicate or express their emotions, particularly to members of other species (ex: humans)? I've been observing a very ...
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Did dinosaurs have more than one brain? If so, why?

I once remember reading (15 years ago) that dinosaurs had two brains. One for their head and another one for their digestive functions. What is the current opinion on this theory? Has more evidence ...
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308 views

intravenous (IV) in the tail vein of an anaesthetized mouse

I trained myself to do intravenous injection on live mice. However, on anaesthetized mice you don't see the flux of your product showing that your injection was successful. In the same way, on live ...
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202 views

How fast can a panda run?

Pandas are going extinct, mostly due to habitat destruction. This leads me to the question: How fast can an average adult panda run? (more specifically Giant Panda)
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Why do snails come out after the rain?

Many times, when there is rain after a long time, snails come out afterwards, and you can see snails and slugs everywhere! I have two questions: Why do they come out after the rain? Where are they ...
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Evolution of spider webs?

Web making seems like a fairly complex behavior built from a pretty strong material. So how exactly did it evolve? Do we have any clues about what kind of features/behaviors preceded web making and ...
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Can animals like squirrels leave “gifts” or tribute for humans?

I've heard anecdotal reports of squirrels bringing up gifts to a person's house after that person left out food for them. Sounds bizzare and unbelievable, until I actually saw some kind of a nut right ...
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Why do men grow facial hair?

Ancestral facial hair. Our closest ancestors, the chimpanzee and bonobo, both grow facial hair around the mouth area. What is noteworthy is that this is the case in both males and females of the ...
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113 views

Why do these earthworms stay between the road lines?

This article shows pictures of earthworms during floods in Texas. The worms ball up, supposedly in order to survive the floods. Can anyone explain the phenomenon a little? I can't seem to find ...
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Burns' “To a mouse” - what species of mouse?

What's the most likely mouse species Robert Burns is referring to in his poem "To a Mouse, on Turning Her Up in Her Nest with the Plough". Burns farmed near Ayr, which is on the Firth of Clyde in ...
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477 views

What makes an animal/species suitable for domestication/training?

Humans have domesticated all manner of creatures during the course of their civilization - dogs, horses, several types of cattle, varieties of birds, and perhaps others too. A prerequisite for an ...
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Zoology - Help identify the kind of spider

Yesterday, I bought a banana tree (Musa Basjoo) from a local supermarket. Today, I noticed a hive of small spiders on the tree. I do not know where they came from, so I am curious to identify these ...
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Help Needed Identifying Corvids

I'd appreciate some help identifying these three corvids I photographed in Austria during the Summer: I know identifying corvids can be difficult, I'm not an ornithologist, just an amateur bird ...
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What is dental health like in animals?

Do animals suffer from tooth decay, such as cavities? Is it to the same extent as in humans, or do animal teeth decay more or less? If teeth decay in animals as well, are there natural strategies ...
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Fetal development, gastrulation and embryonic disc

I am completely confused by the images circulating on the internet of human gastrulation. First, lets see how it happens in deuterostomes. This image depicts the process: (image is from Wikipedia) ...
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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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Is the theory of evolution being disproved by bats?

For some species the Darwin's theory evolution makes perfect sense. I can easily imagine how, for example, the giraffe has evolved to its current appearance: the natural selection was favoring ...
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Do male animals visually perceive females as more/less attractive?

If we somehow remove pheromones, do animals experience a phenomenon similar to human "visual beauty" when looking at members of the opposite sex? For example, given a set of 20 female ducks observed ...
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271 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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The number of nipples (breasts) a species has?

Only mammals have mammaries and mammary glands. What evolutionary factors determines the number of mammaries (nipples/teats/breasts) a species has? Is it always an even number?
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Is life expectancy linked to intelligence in animals?

For example, animals that live only a few days or a few years are often not very intelligent. In contrast, the most intelligent animals seem to live longer. Is this true? Are there any studies to ...
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215 views

What is called the “area size that an animal usually lives in”?

What is called the "area size that an animal usually lives in" or "needs for a normal life"? Is there any specific term?
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Body size, what are the evolutionary trade-offs?

Background Considering just the "Kingdom Animalia" branch of organisms. It is clear that bigger does not necessarily mean better - there is large variation in body size... From the 94 µm long ...
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Why are (some) cats attracted by bleach?

(Sorry if this question is only partly biological) I have noticed that several cats (including the one that keeps sleeping in my house), are fond of the odor of bleach (eau de Javel) and chlorine. ...
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How can a drone be male?

A drone bee is male and is the product of only a queen bee. How is it that the drone bee can be male. I know that a drone is produced by an unfertilized egg, but this does not explain where the two X ...
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Are these cats calico?

Calico cats are cats that have 3 fur colors and are always female or males two X chromosomes. I've seen many cats that will have 2 fur colors (one of them is usually white) and another, third, color ...
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Polymorphism in cnidarians?

To me, the phenomenon of polymorphism in cnidarians is particularly troubling. I gather that it essentially refers to existence of various different forms or kinds of individuals, i.e. zooids and ...
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Which class of animals constitute the largest biomass?

I found here that species-wise it is cow. But, collectively, insects may exceed even mammals. So, which class of animals constitutes the largest biomass?
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Which Darwin book (and today edition) is illustrated by his own drawings?

I am interested in buying Charles Darwin books and mostly drawings (nowadays editions, I am not a collector). Please, can you advise in which book and which edition I can find the most of his ...
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774 views

Help me Identify this Spider

This red spider has set up a web in my yard, in South Eastern, Texas, United States: The spider itself is about an inch long (2.5 cm), and is predominantly red to brown in color, with red legs, and ...
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Has an artificial symbiotic relationship ever been created?

Have 2 organisms ever been introduced to create a symbiotic relationship that doesn't occur in their natural environment?
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112 views

How to know the gestation time of pregnant mice?

In lab mice I wish to establish how many weeks my animals are into their pregnancy. Is there some way?
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541 views

Why does cucumber skin kill ants?

I recently read that cucumber skin is an effective repellent for some ants: Set out cucumber peels or slices in the kitchen or at the ants' point of entry. Many ants have a natural aversion to ...
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216 views

What's the name of this caterpillar?

It was found in the state of Virginia, on the east coast of the United States.
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How do animals handle light refraction in different media?

For a human, when diving underwater, everything is blurry because of the water's different refractive index compared to that of air, which we are accustomed to. How do animals, like turtles, seals or ...