So there's now 2 cats living together that weren't before?
Do they get along with each other or are they avoiding each other, hissing, fighting etc. Is there any competition for food?
Were they introduced slowly to each other or just both put into the new house together?
Do they have places to go to get away from each other for a while?
Avoid biting when a simple growl will do
The Spirit Lives As Long As Someone Who Lives Remembers You - Navaho Saying
Vindication ~ For all those pets who became sick or lost their lives from tainted pet food