Frogs are coming as you have a water source nearby. Eliminate the water source. Standing water in a pool. old boat, creek etc. Toads are different from frogs.
Why? They eat bugs and insects.
I wish I had some frogs in my flower bed! They eat all sorts of things we don't want such as slugs and mosquitos. We don't really have frogs here though. Too dry.
Why would you want to eliminate them? They eat harmful garden bugs.