How do mouses urinate?
Mice don't usually have a great deal of bladder control--they
just let go when they need to. If you hold a mouse for any length
of time, you will probably get peed on. However, it depends on the
mouse, too--tame mice who trust you may wait awhile until they HAVE
to go on you, and may even wait until you put them back in the
cage. Mice who don't trust you will pee on you as soon as you pick
them up. Some mice will also choose to pee in a certain corner of
their cage, but many of them don't care. Like dogs and cats, male
mice will use their pee to mark their territories.