One of the hamsters i was ranting on about yesterday (the one that desperately needed a bath) seems to have something wrong with him. He seems a have a very large lump on his back end. I first thought that his balls were swollen but the lump seems to be under them. The lump must have been there for quite a long time as it's the size of a golf ball! He walks around quite slowly but is eating (a lot) and drinking fine. I will be going to the vet with him asap but just wanted to ask if you have any ideas as to what it can be? I'm hoping it is just an infection he's got as, well, you saw what a mess he was in, right!!