Is there a way to tell if my yarn is wool?

[lemonapple]

Hey fellow yarnies,

I picked up two large balls of yarn from my local thrift store...and I'm wondering if one of them might be wool. I'd be so excited if it were wool because I've been wanting to knit a pair of shorties. Is there any way to tell for sure?

Thanks!

[motherbirth]

Here are some tips.

The one I knew was burning a piece of it, but if you do it, be careful.