Category: Animals

Rabbits thump their hind feet mainly as an alarm signal.

A strong strike against the ground creates both sound and vibration.

Why is that useful?

Wild rabbits are prey animals.

If one detects danger, a thump can warn others even when they are not looking in the same direction.

Ground vibration can also travel into burrows.

What can trigger a thump?

A strange animal.

Sudden movement.

An unfamiliar noise.

A new object.

A household appliance.

Domestic rabbits can react to things their humans do not consider remotely threatening.

The rabbit gets a vote on what counts as suspicious.

Does a thump always mean fear?

No.

Rabbits can also thump when frustrated or annoyed.

The rest of the body and the situation matter.

Why are rabbit hind legs so powerful?

Rabbits depend on strong hind limbs for fast acceleration and jumping.

The same muscles make a foot strike loud and forceful.

What should you do if a pet rabbit keeps thumping?

Look for a possible source of stress.

Provide hiding places and reduce sudden disturbances.

A major behavior change combined with reduced eating or abnormal posture deserves attention because rabbits can hide illness well.

This is another good example of animal communication, just like frog calls or dog scent marking.

Most of the time, the rabbit is sending a simple message:

Something has my attention.

Everybody else should probably know about it.

And that’s the short explanation.

Related explanations: Why do frogs croak?, Why do dogs kick the ground after they poop?, and Why do animals have tails?

Cats’ eyes seem to glow because of a reflective layer behind the retina called the tapetum lucidum.

The eye gets a second chance at the light

Light enters the eye and reaches the retina.

Some light passes through without being absorbed.

The tapetum reflects that light back toward the retina.

That gives light-sensitive cells another opportunity to detect it.

Why is that useful?

Cats are adapted for low-light activity.

Large pupils, many rod cells in the retina, and the reflective tapetum help them make better use of dim light.

They still cannot see in absolute darkness.

There has to be some light to work with.

Why can we see the reflection?

Some reflected light exits the eye again.

If you are near the original light source, such as a flashlight or camera flash, that returning light can travel toward you.

The result is eyeshine.

Why can the color vary?

The color depends on eye structure, pigments, viewing angle, and incoming light.

Green and yellow are common.

Is this what fireflies do?

No.

A firefly creates light chemically.

A cat’s eye is only reflecting existing light.

The visual system is also part of why goats have unusual horizontal pupils, though goats solve a very different problem.

Cats’ eyes are not making light.

They are extremely good at sending available light back through the eye.

And that’s the short explanation.

Related explanations: Why do goats have rectangular pupils?, Why do cats have whiskers?, and Why do cats slow blink?

Dogs often turn in circles before lying down.

The behavior probably combines inherited nesting habits with a very ordinary desire to get comfortable.

Wild canines rested on uneven ground

Grass, leaves, dirt, and vegetation are not memory-foam mattresses.

Turning before lying down could help flatten plants and arrange a resting spot.

Circling may also help inspect the area

Moving around the spot gives the animal a chance to notice unpleasant objects, insects, or other problems before settling.

Modern dogs keep old behavior

Inherited behavior does not disappear just because the environment improved.

A dog may perform three careful circles on a perfectly flat bed you washed yesterday.

Why do dogs scratch the blanket too?

Pawing can rearrange bedding.

It may also leave familiar scent from glands around the paws.

That fits with other scent-based dog communication such as kicking the ground after pooping.

Is circling always normal?

A few turns are ordinary.

Repeated restless circling, difficulty lying down, pain, or a major new change in behavior can be different.

Older dogs with joint pain or cognitive changes may have more trouble settling.

So the circling is probably part instinct and part comfort adjustment.

The bed is ready.

The dog just has to inspect it like a building contractor first.

And that’s the short explanation.

Related explanations: Why do dogs kick the ground after they poop?, Do dogs dream?, and Why do dogs wag their tails?

Dogs probably dream.

They move through sleep stages that resemble those seen in humans, including REM sleep.

Dogs enter REM sleep

REM stands for rapid eye movement.

During this stage, brain activity becomes relatively active while most large skeletal muscles are inhibited.

Humans report vivid dreams especially often after REM sleep.

Dogs also enter REM.

That shared sleep architecture is one major reason scientists think dreaming is not uniquely human.

Why do dogs twitch and make sounds?

Small movements can break through normal muscle inhibition.

A sleeping dog may twitch paws, flick ears, move the face, whimper, or make small barking sounds.

Those movements are consistent with dreaming.

They do not tell us exactly what the dream contains.

A paw twitch does not scientifically prove there is a squirrel involved.

What would dogs dream about?

We cannot ask them for a report.

Research in other mammals suggests sleeping brains can reactivate patterns linked with waking experiences.

It is reasonable to think dog dreams draw from movement, smells, social interactions, play, and familiar places.

Should you wake a twitching dog?

Usually not.

Mild twitching is normal.

Suddenly waking a sleeping dog can startle it.

Letting the dog wake naturally is generally better unless there is a safety concern.

Is dog dreaming related to human dreaming?

Yes.

Humans also experience dreams that can feel extremely real because the sleeping brain remains highly active.

The plot is probably different.

The basic sleep biology has a lot in common.

Dogs probably dream.

We just do not get the morning review.

And that’s the short explanation.

Related explanations: Why do dreams feel real?, Why do dogs circle before lying down?, and Why do dogs tilt their heads?