Thanks! I was thinking it was a bit slippy so I was keeping an eye on it. I'll put some more shelf liner in the brooder.
I don't have a coffee grinder but I did run it through the food processor which I read somewhere. It did leave bigger chunks but most of it is small and powdery, and they were eating the smaller bits.
I just ran it through a sieve and I got a very fine powder, is that too fine? If I put some of the larger pieces in will they just eat around the bigger chunks or will they choke?