We're renting... the bathroom has a lock... it turns on the inside. On the outside it's just a tiny hole.

I do not know who makes the lock but I am hoping someone can tell me how to unlock it as my husband locked the door and then shut it on his way out
I've put a small straw in the hole trying to feel around but I am not sure what I am looking for. I tried to look at other locks in the house (all the same) with a flashlight but the hole is too small.
Any advice?