Rat Q?????????????????????????????…

There is a rat in my garage i saw it go under my mom's car and we have traps in there but the rat never goes to it.I thing the rat has been there for 2 weeks. I am all agansit animals be killed but i just dont like rats.How do i get it out of my garage? We have a little opeing in the garge door that opens maybe that how it got in idk.Help! thxs