Diseased mouse?

So today is feeding day for me and the local pet store only has mice and my snake has no problems eating them. I buy the mouse around 2pm today and I put him in a plastic container to hold him until tonight. Well the mouse was doing back flips for over an hour then died. I wonder what if anything would have happened to my snake if he would have eaten him? Anyone ever have this happen? I took the mouse back and got another one with no problems.

Yeah. I bought a mouse from a Pet store(one of the chain stores) and the mouse was fine when I got it around 4 pm and it looked perfectly healthy. My snake refused it so I put it into a 10 gallon tank I had and gave it water and some food. I went to check out it at about 9pm and it was dead. I figured it died of stress. I read they can get stressed out pretty easily.

a lot of times also they might have been inbred, which would make it act weird and die quickly...
i used to breed mice, but before i started i bought my mice from small places that kept male and female mice together in the same cage which really led to inbreeding...

Feeder mice aren't usually kept in the best kind of conditions when it comes health and breeding. They are there to sell to people to feed off. Most stores that sell feeders keep them all together and the tubs/tanks are over crowded and they don't get cleaned often enough. A lot of them are very sick and don't live that long. Also even healthy appearing ones have been known to just die. Mice don't have the best immune systems.