Mishna Berura 471:2:12 says there are those that do not eat Matza starting Rosh Chodesh Nissan. May one eat Matza that is Chometz?
I have hamsters at home, and their usual food is chometz. I can feed them with cornflakes and other kitniyot for a short period (about a week, maybe more), but not for a long time. Hamsters store food ...