So.. I feel horrible about this.. but one of my rats is not very friendly.. doesn't like being touched or held really besides a little side scratch every once in a while. Today he was on a position where I decided to just run my palm down his back.. which I normally don't do because he doesn't really like any attempt/motion to pick him up and I felt a rather large lump.. or course I then just grabbed him and took him out of the cage wrapped in a towel. The lumps is maybe a little smaller than the size of a nickel and is rased.. but freely moveable and not attached to anything under the skin.. it has the appearance of a huge blackhead (gross.. sorry) and is firm.. not compressible at all..and has some dark material dried up at the center (which reminds me of a blackhead)... I'm thinking that maybe this was an abscess that dried up and is all hard now? I tried warm compressing it this evening but I don't think it is going to do much.. any suggestions on what to do? Will these guys just eventually pop out and go away? Any idea what it could be? I was really suprised that something so big could be hidden my his hair.. but it isn't noticeable at all under his coat.