What if mice get in a guinea pig cage are they safe?

not unless it reaches in and scratches it trust me, i had a guinea pig and a cat and the same thing happened <------ very good answer, im just going to add some more.

my new and improved answer:

yes, the cat will reach in a scratch it, grab it and hurt it, the guinea pig might think its ok, and walk over to the cat paw and the cat will swipe at it and claw its eye... this happend to me.

thank you

hope i helped