mouse cliques?

Question
do mice form cliques? It may sound silly, but I am sort of scared that if I get five mice, four from one litter and one from another, they might leave the one out.

Answer
Dear Arie,

It isn't such a silly question.  Just like when a new student goes to school, the other students don't know her and she may not get invited to  parties (whatever) right away.

The four mice know each other and are accustomed to their smells.  I assume the fifth mouse is from at least a different cage.  The new mouse has a strange smell and four mice will find her different and potentially an enemy.  Thus they will, in a way, gang up on her.  Each mouse may consider it her duty to show the new mouse who is boss.  A lot will also depend on whether the new mouse wants to be boss, herself.  In  most mouse groups, one mouse is the top mouse and she keeps the others in hand by chasing, mounting, and washing them!

However, the chasing won't go on forever.  First, there is a trick to making the mice think they all smell alike:  Put a tiny dab of REAL vanilla extract on each rump and chin.  You can do this a few times as they begin to get to know each other.

Chasing and squeaking are normal. I only worry if there is blood.  If nobody bites anybody hard enough to bleed, then they are just going through mouse rituals.  The squeaking is not pain, it's communication.  I recently put 3 new mice in with my peaceful mouse triplet.  There is still some noise happening-- there are two mice who each want to be top mouse, so they spar, and the two of them, plus one more slightly aggressive mouse, each still chase the baby at times.  When I am around I will take the chaser or the baby out of the cage to give her a break, but sometimes I just leave them to squeak.  

As long as the existing mice let the new one sleep with them (make sure there is only one nesting area), and nobody bleeds, everything is ok.  Good luck and have fun!

squeaks n giggles,

Natasha