Gerbils and mice are both rodents and look very much like each other.
Their physical appearance can food the untrained eye into thinking one is the other.
So can gerbils and mice breed at all?
It’s very unlikely a gerbil and a mouse could breed and produce a hybrid.
Hybridizing requires two closely related species and just because they happen to be rodents, doesn’t mean that they can breed.
If a gerbil and a mouse were put together, then before they even thought about breeding they would be fighting.
As they are both very territorial animals, it would be a fight to the death unfortunately.
They are best keeping away from each other.
So never put the two species together and all will be well.