Sheet metal and hardware cloth are very effective for rat-proofing. Remember, a rat can enter an opening that is just one half inch across. Remove sources of food When done properly, trapping can be a good way to control rats. Successful trapping depends on knowing the habits of rats. Remember rats tend to use the same runway.
Traps placed in the runway are most likely to work.
Trapping may be more successful if the trap is left unset for several days. Rats are shy of new objects, not human odor. If baited, remember rats prefer fresh food. Peanut butter, apple or cheese, make good rat baits. If there are only a few rats, trapping may be the quickest and safest way to remove them.