The biological study of animals.

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17
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1answer
183 views

What effect does a bat's echolocation have on other bats?

Bat echolocation is a perceptual system where ultrasonic sounds are emitted specifically to produce echoes. By comparing the outgoing pulse with the returning echoes, the brain and auditory nervous ...
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0answers
60 views

Locomotion of Hydra: Why Somersaulting is better than Loop locomotion when moving to a larger distance?

In my text I read about different types of locomotion of Hydra where I learnt that generally Hydra moves by somersaulting and it is faster than 'Loop locomotion' which Hydra uses for moving to a large ...
2
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0answers
35 views

Why is it called Nematocyst “Battery”?

I was reading an article on Hydra where they mentioned Nematocyst Battery. I know that Hydra and other Cnidarians have nematocyst but why are they called Nematocyst 'Battery'?
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17 views

Are there more efficient forms of sleep among mammals?

We know that there are 4 distinct sleep stages among humans and we need about 5 sleep cycles each night. With this in mind, are there mammals that achieve their sleep needs more efficiently? I'm ...
2
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1answer
46 views

Why are compost worms sensitive to light?

I read that compost worms dislike light. But I'd say they don't have eyes and I couldn't imagine their skin is sensitive to light in general, is it? And if so, then why?
4
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179 views

Are there animal species with sex of an offspring determined by sex of preceding offspring?

For instance, if an animal's first offspring is male, then all subsequent offsprings will be male too (the sex of first offspring could be determined randomly). Does it happen in any species?
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45 views

Can immortality of the Turritopsis dohrnii be learned or adapted by other species?

I have heard that Turritopsis dohrnii is a species of jelly fish which is immortal, as it can grow old and then back to growing young. So, how is it possible? Can other species (marine and/or land) ...
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96 views

small cocooned caterpillar found on bathroom door - what is this creature?

This larvae / moth has what seems to be a smooth gray cocoon which looks like a piece of cement. It can carry this cocoon with it as it crawls, and it can come out from both ends of this cocoon. Would ...
4
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1answer
129 views

Unknown animal - What could it be?

It's the first time I use this website and I really need help because I'm totally stuck Now I'm in school, but I'm trying to prepare for the Olympics During the preparation, I found the issue on the ...
2
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1answer
326 views

Why would villagers attack Orangutans?

I read today in the news that villagers in Borneo were attacking refugee Orangutans. Why would they do this?
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37 views

Is pathlength correction vital to be included while quantifying protein

I am trying to quantify protein in serum/plasma samples. I have carried out biuret assay for my samples using microplate reader. While performing I encountered the doubt whether I should include ...
1
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1answer
46 views

What do “reduced antipredator defense” and “reduced antipredator vigilance” mean?

The book BIOMAT 2010 (International Symposium on Mathematical and Computational Biology, edited by Rubem P. Mondaini) mentions the terms reduced antipredator defense and reduced antipredator vigilance....
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30 views

Which metazoans host anaerobes to aid in digestion? Do any host oxic digestive tracts?

Many metazoans (e.g., mammals, insects, earthworms) have anoxic digestive tracts that are colonized by anaerobic microbes that perform portions of digestion of food for the host. Some other metazoans ...
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12 views

Do other primates get gallstones?

Which non-human primates actually get gall stones the same as humans? All, some, none? References appreciated! Anecdotes about pet primates with gallstones also welcome if you have any...
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2answers
257 views

Examples of prey predator interactions where density of predator is very low and prey form groups when the predator attacks the prey for food

Examples of prey predator interactions where density of predator is very low (has a threat of extinction) and prey form groups when the predator attacks the prey for food. I have searched this in ...
2
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2answers
55 views

Identification of this species of Toad

I found a short -- 20 second/s -- video on the Internet of a toad and I wonder if anybody could identify it? Here is the hyperlink; http://weloveshortvideos.com/post/132047898162 It was posted on a ...
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14 views

Steppe peoples method for healing horses' wounds

There was a custom among nomadic steppe peoples like Huns or Mongols of putting pieces of saltened meat in wounds of their horses to make them heal faster. Did it work? If so, how? I suppose it has ...
6
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2answers
3k views

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 ...
3
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1answer
149 views

Why are cancer rates low in large animals?

Large animals generally have more cells and live longer than smaller animals. For example, bowhead whales live up to 200 years and weigh up to 100 tonnes, as opposed to humans (living ~71 years and ...
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1answer
44 views

How can birds keep their eyes moist during flight? [duplicate]

Mammals have an upper lid and small mass of tissue in the upper corner known as nictitating membrane. This helps keep the eyes clean; birds can moisten their eyes in flight using this membrane ...
5
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2answers
90 views

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 ...
4
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1answer
102 views

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?
3
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1answer
102 views

Please identify organ

This is the gut area of an Eastern Grey Kangaroo taken of a property in the Southern Highlands of NSW, Australia. The top red organ appears to be the spleen but what is the elongated tubular organ ...
4
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1answer
70 views

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 drawings?...
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33 views

Is lung size/shape a factor in long-continuous running of animals?

Apart from other factors, does lung shape/structure/size play any role in long-continuous running animals. Is there any similarity in lung structure between different long-continuous running species?
0
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1answer
136 views

The biggest underground living animal

It's easy to find informations about the biggest animals at land / at sea / in the air. But what was the biggest animal that ever existed, that lives underground? No animals that were forced to live ...
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296 views

is a musk deer's musk pod in its abdomen, its back, or its bottom/rear end?

I have read/heard different things about where a musk deer stores its perfume Some links say it stores it in its abdomen just in front of its penis. Others say the rectum(by which I suppose they ...
21
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5answers
4k views

Why are there no known animals with an odd number of legs?

In my 6th grade science book it is said that there are no three legged animals, and that no animal with an odd number of limbs exists. I checked Wikipedia and could confirm this: There are no ...
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51 views

Was this snake behaving abnormally?

This morning, I walked out front of my house to find a medium-sized snake balled up on my driveway beneath my motorcycle. I spotted it from my porch so I didn't walk any closer. I believe it was a ...
0
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1answer
45 views

Biological Evolution outside of Earth [closed]

What drives evolution forward? I heard that climate change drives species to evolve and adapt. Is there any other mechanism that is encoded in our DNA by which species can over abrupt changes, evolve ...
5
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2answers
311 views

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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0answers
38 views

Why do I often see male robins with female robins?

Even when it is not breeding season for robins I still often see male robins with female robins. But why? I know that the male robin often chirps to find female robins within his territory. I also ...
0
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2answers
54 views

Do any predatorial animals attempt to appear smaller?

There are many animals that have behaviors or characteristics to make themselves appear larger than they are as a defense mechanism, such as butterflies have large eye patterns on their wings. Are ...
5
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1answer
218 views

What is a subspecies?

Within a species there may be subspecies that are named using trinomial nomenclautre. For example the Grizzly Bear, Ursus arctos horribilis is a subspecies of the Brown Bear Ursus arctos. The ...
2
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1answer
81 views

Do all mammals have a Ventricular system?

I am familiar with the human Ventricular system that circulates Cerebrospinal fluid. This is needed among other reasons, to suspend the heavy human brain, and for injury protection. Do all mammals ...
7
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2answers
451 views

Why Egg shell is not called a cell wall?

Egg is a single cell and has a outer hard covering outside inside which there is a cell membrane. Then why isn't the egg shell a cell wall? Is it because no exchange of materials take place through ...
4
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2answers
130 views

Which primates can swim underwater?

I saw a documentary awhile back and they were profiling a certain species of monkey which regularly swims underwater. I can't recall which species it was but they said it was rare for primates to do ...
3
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1answer
113 views

What type of jellyfish is this

I have been swimming in the seas around Minorca and saw a jellyfish I had not seen before. I have tried to find it and have (eventually) found 1 single picture of the jellyfish. The problem I ...
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0answers
19 views

How much oil you can get from a dead animal

This is purely speculative, but is there a formula to calculate how much oil you can get from 1 Kg of biomass? I've seen bioreactors in farms where they put dung, vegetable scraps, and all bio scraps,...
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27 views

can the regeneration mechanism be used in humans that of lizards?

how lizards grow their tail again like is there any mechanism or specific protein which helps them to regrow their tail? can the mechanism of regeneration be used in humans to regenerate our limbs is ...
4
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1answer
125 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?
5
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1answer
435 views

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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0answers
48 views

How octopus develops its imitation skill?

I've watched one documentary about a Mimic octopus which they can imitate another animals in several form e.g. a Lion fish, a Sea snake, a Flatfish, etc. My question is how these octopuses can have ...
6
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3answers
176 views

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 ...
2
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1answer
170 views

The heart of a Pigmy Shrew beats 1300 per minute then why is it so fast?

A pigmy shrew is such small animal. Even with such fast heart beat their average life span is 1.5 years. So can we consider faster heartbeat not good for health?
5
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1answer
281 views

What kind of insect is this and what is it doing?

I live in Denmark, Europe and found these 2 insects on a tree. I'm interested in the big fly and have the following questions: What kind of fly is it? What is it doing with the little fly?
7
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3answers
292 views

Insect identification: white spotted beetle

3 pairs of legs, a pair of antenna, wings absent, compound eye, 4-6 centimeter approx. in size. I found this beetle at my door, in Pune, India.
7
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2answers
368 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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0answers
387 views

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, ...
3
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2answers
64 views

Madrid, Noise by the river: Bird or cricket?

I currently live in Madrid, Spain. In July there was a loud animal near the river, in an out of town area surrounded by grassland, with trees along the river. It's continued into August, though it ...