How large is the cage? Sometimes this happens when males become sexually mature and it usually calms down. Did he draw any blood?
Sorry took so long to reply.
The cage is half a 6ft something rat cage. I think its about 3.5ft-4ft. It just the 2 of them, they have platforms and rope and a bath and a wheel and loads of tunnels and toys, plus there toilets. They also come out to play when ever I have a spare minute, try to let them run free for aslong as they wish. usually about a hour and this week we introduced them to our guneia pigs and they had a free run together. But that was after the first incident and before this one. So I do not think it could be that.
No blood but the strange thing is I have just cleaned them out again today, (I do it every sunday and thursday) And again they had a little fight when they both went back in it out of there tank they go in when I clean them out. Once again monty is hidden in the tube and Dobby is running around being normal.
Its v strange. It has only happened the last two times I have cleaned them out and had them for just over a month now. They were already 6 months when i got them. I adopted them from a pet shop rescue bit as their original buyers returned them because they didn't get on with the females they wanted to mate them with.