Bats – how do they know it’s night?

Bats are blind and nocturnal. How TF do they know it’s dark outside?

They’re not blind.

Uh, how have you managed to get this far in your life without knowing bats have perfectly good eyesight? They don’t use their eyes to hunt, and they’re not completely nocturnal, like owls they are sometimes crepuscular, they can fly when there’s still light in the sky, in fact that’s when they start to hunt. They use echo-location, and different species can be identified by their distinctive ‘chirps’.
I’ve watched bats flying around my garden at twilight, sometimes earlier.

They’re not blind.

I’ve been lied to my whole life.

bats have perfectly good eyesight?

Now I come to fink about it…

Hormonal changes driven by circadian rhythms.

These are entrained by changes in light.

Hamsters running on wheels are the classic way of studying this.

Haven’t paid attention to the actual biochemistry for decades but it’s bonkers complicated and dtives everything from wheel running in hamsters, through egg laying in chickens to bats coming out to hunt.

Another mind blower for you… most ‘blind people’ aren’t actually totally and utterly blind, as in they literally can’t  even tell differences in light levels.

I’ve been lied to my whole life.

Bats being blind isn’t the half if it!

But they obviously aren’t blind or the Bat Signal would be useless.

I think the OP may have  had a bit of sprout poisoning or some bad Eggnog 😉 🙂

I’ve been lied to my whole life.

At least I can confirm that posts are actually deaf.

OP

Nevermind bats,what about moles,how do they know which way is UP?

I’ve always been curious what it is about boxes that makes frogs go mad.

Think this was on QI recently. The idea bars are blind came from a “scientist” that removed bats eyes. Because they could still fly and not hit things, he deduced they must be blind and use another method to navigate.

Dolphins aren’t blind either.

Nevermind bats,what about moles,how do they know which way is UP?

Because it’s the only way.

The idea bars are blind came from a “scientist” that removed bats eyes.

Just gave me flashbacks to when I was a kid and heard “Three Blind Mice,” and was appalled when the farmer’s wife cut off their tails with a carving knife. What a ****.

Dolphins aren’t blind either.

Sounds fishy to me

Bats are blind and nocturnal. How TF do they know it’s dark outside?

Do they know it’s Christmas time at all?

Sounds fishy to me

Because dolphins use echolocation despite having perfectly good eyesight?

Because it’s the only way.

Baby!

The idea bars are blind came from a “scientist” that removed bats eyes.

I suspect this is a myth on a par with “bats are blind”.

The pub’s open.

At least I can confirm that posts are actually deaf.

What about Listening Posts?

I imagine they set their alarm clocks

“Holy early evening alarm call Batman!”

Nevermind bats,what about moles,how do they know which way is UP?

The breath out and look which way the bubbles go.