I've got the "professional" exterminators coming, but what else can we do? What should we expect from the "professionals" as well?
D-Con, and lots of it.
They'll set traps with peanut butter. Maybe some glue traps, too. The more the better. Outside they mey install some bait stations. They should inspect to find out where they may be entering.
You can help by being persistent about where you hear them and passing that info along. Also
Rodents want the same things we do -- food, water, and a warm place to sleep. Deny them those things. If you have any kind of pet or bird food, make sure it's properly stored (use a metal trash can with a tight fitting lid in the garage). Keep the kitchen clean and eat in one place so eliminate any spills or crumbs falling to the floor. Clean up any dropping and wash/disinfect the area. Rodents pee and pooh as they walk. It also serves as a road map for them or others. Seal openings, they can get through a pretty small hole.
Are you sure they are rats or, are they mice? Mice generally stay within a 12 foot area of a water source. Rats do a bit more traveling. That means if there are openings, they can leave the house for the water source and re-enter. If they can get their nose into an opening, they can wriggle their body through it. Then they'll gnaw on other things for food. Either way, mike kaiser offers the best advice to make them go away on their own. The poison and traps will get rid of the ones that are there now. However new critters, in their search for food, water, housing will enter openings in their search. They just won't stay if you do as mike mentions. That means you'll still have to disinfect on a regular basis.
We had a problem at church pantry. They told us rats just come back through minute they dry-walled it in. We put sheet aluminum in front of holes allowing large area to be covered. Painted it same color as rest of room & never have had a rat return since 1989. They were coming in under the building.Did put screens back over crawl holes (plumbing & electrical under there) that were screwed on & heavier than before.
The tell tale sign of rats is digging. If you see holes dug all over the place you probably have rats. If not, then perhaps you have mice.
The other tell tale sign is seeing one!