Is it in the attic? Good chance they are squirrels not rats. Squirrels are on a similar schedule as humans so you’ll hear them early in the morning and evening. Go outside and look for holes in the soffit. It’s a common place for them to get in. You can have one way doors installed so they can get out but not back in.

Our apartment we moved into last August was infested with them for years. Last tenant just didn’t care I guess. Did a ton of damage. Pissed and shit all over the insulation which had to be replaced chewed wires and 2x4s. Their teeth constantly grow so they have to chew on things to keep them the right length.