Fairly new at knitting and my maiden voyage into talking (?) online (?)
Anyway a great site, have made a few hats and want to make the felted hat with the eyelash yarn on the brim. Can I use regular eyelash yarn? What will happen when I go to felt the hat?

Welcome to KH, online communication, AND knitting!

I've included non-wool yarn in felted items before (such as eyelash yarn), and everything wool felted and the non-wool stuff didn't. Basically, what happens to the non-wool yarn is it gets washed! :-P Hence, it stays the same (unless for some reason it's really fragile yarn and gets torn up, but I've never had that happen).

If you're really worried about it, knit a small square of half wool and half eyelash yarn, and then felt it to see if you like the end result!!

Wonderful suggestion! Thank you for answering my questions - I'm on it!