What are treats?

What are treats? Why is everyone following Foster Mommy around when she said we were going to get them? I followed because the others were, and she pulled out a crunchy bag from a drawer. Tabby "asked" the bag so she could have whatever it was in there, and Rori talked to it. Must be something good. But then Foster Mommy poured out these things that looked kind of like our food but smelled different. I didn't know what they were, so I ran and hid. I watched the others gobble them down, and Foster Mommy brought one over to me, but I sniffed it and walked away.

P.S. I'm not in heat anymore, so I'm doing fine being out with the others again. Rori and I are playing normally, chase and all my favorite games.