Why is Mouse lord Ganesha's vehicle?

The mouse becomes Ganesha’s last vehicle during his last incarnation. It has been said that the reason why he has this vehicle is that he is the Destroyer of Obstacles. The mouse makes it easier for Ganesha to go through small space and get rid of the obstacles that may be there so that things will become more smooth sailing. Another reason for this is because this is the symbolism that Ganesha was able to handle his pest which is something that we should also do in real life.

We sometimes let the things that hinder us from achieving our goals to actually stop us. The best thing that we can do is to fight our pests so that we can move on. The only time that we are able to control our weaknesses will we be able to go through our many obstacles easily.