Hard to tell anything by this picture but it looks like regular movement due to expansion and contraction. Just needs to be calked.

Looks like a minor crack... However, I hate cracks in the foundation corners. Go check your basement.

I have seen watered down sump from this one foundation contractors that would always crack in the corners. If you are GCing, always always be present at @foundation pour. Make sure they vibrate the corners and not go like SUMP #7 with added water, so it is easily flows into the corners.

While that hole is large enough for a mouse to get through, that wouldn’t be my first thought on why it’s there. Not unless the cat sits and stares at that spot. If you do have rodent issues, there’s nothing like having organic rodent control to handle them though!

Looks like a poor drywall finish to me.

I highly doubt if the mice did that good of a job drywalling. You may have more to worry about if you DIDN'T find mice outside the window.