Okay so I had a cage with two feeder mice inside (1 male, 1 female). I decided to go out an buy three more to see if I would have any better luck breeding them to my 1 male. About 24 hours later, give or take, 2 of the 3 that I purchased were dead, just laying in the cage. This was about 4 days ago, and the other one is still perfectly fine. Could there be an obvious reason for this? Could they have been diseased or something?

I have the two dead ones in the freezer now, should they be safe to thaw and feed to my ball or should I just toss them to be safe?

I'm confused, and novice. Obviously.