What creature is making this sound?

Question

I live in Alabama, and in the summer time I always hear this screetchy/creeky sound. It'll get louder and softer during the day. I was just wondering if anyone knew what kind of insect it may be.

Btw...I'm sure that it isn't crickets...

Answer 1

You sure its not tree frogs?

Answer 2

Sometimes squirrels or birds will make that sound.

Answer 3

It's probably cicadas.

The "hum" of a cicada will gradually get louder and louder and then after a few moments will get softer and softer... and then repeat.