breeding gerbils and mice

Question
i have three female white mice and one brown male gerbil, the gerbil was very unhappy by himself so i put him in with the female mice. They were mean and territorial in the beginning but now they are very happy and comfortable together. but now i am afraid they will mate with each other....is it possible?

Answer
No, it's not possible. But I still don't recommend housing gerbils with mice. Nearly every other small rodent is a mouse predator or aggressive enough to kill a mouse, and the situation ends in disaster. If your gerbil is lonely; considering getting him another gerbil or spending more time with him.