I have (had) three adult mice and a litter of babies in one tub. They seemed completely fine yesterday and then today I checked on them and they were all dead, all the babies and the adults exept for one adult. I think I might have an idea, I was feeding them on "High Protein Retriever" (dog food). But they've been eating that for about 6-8 weeks since I got them, you think that's the reason?