What are the sounds you hear from insects in early day in late summer?

Question

I am not sure if these are crickets or something else.

but sounds like a humming kind of noise coming from insects.

does anyone know what this is and why do they call out in late summer instead of earlier in the year?

is this a mating call?

and for how long do they do this before they stop?

Thanks for your answers!

Answer 1

It depends on where you live in Illinois we here tree frogs which sound a lot like insects and also locusts and related bugs, they are mating calls and also bugs rest when it is cool!!

Answer 2

the sounds you are hearing most likely comes from the cicada

http://en.wikipedia.org/wiki/Cicada