that last bit tells me you're either old or have hearing damage: we have some bats around me and despite never once seeing them it's plainly obvious to me that they exist thanks to their shrill squeaky calls in the twilight.

https://www.youtube.com/watch?v=X4eqkaHkTAI

[–] norbert@kbin.social 6 points 4 months ago (1 children)

Linking to a guy using an expensive ultrasonic mic to hear bats doesn't really support youe statement that you're hearing bats around you despite never seeing them. Maybe you have hearing damage?

[–] Swedneck@discuss.tchncs.de 2 points 4 months ago (1 children)

he literally says in the video that their calls range from 20kHz to 200kHz, with 20kHz being the normal top range of human hearing for someone without hearing damage.

[–] norbert@kbin.social 3 points 4 months ago

WHAT?

[–] saigot@lemmy.ca 4 points 4 months ago

Some species of bats spend more time in the upper ranges that no human can hear than others.

The spotted bat for instance, is found on west coast if North America and mostly calls at 11khz well within even older human hearing while other bats operate entirely outside human hearing.

[–] PotatoesFall@discuss.tchncs.de 1 points 4 months ago (1 children)

Interesting. Probably the species around where I live don't make much noise, nobody else hears them here

[–] Swedneck@discuss.tchncs.de 2 points 4 months ago

maybe swedish ones are just constantly death metal growling