Get a bottle of peppermint essential oil and put some on cotton-balls. drop these in areas behind your stove, entry points and in places they like to hide. Rats hate peppermint. Do this in conjunction with other methods to get rid of them.
The following websites offer great info on organic pest control in the charlotte area.
www.pestcontrolcharlotte.net
www.fortmillexterminators.com
www.gastoniapestcontrol.com
Charlotte Pest Control
www.charlotte-pest-control.com
Charlotte lawn care