We had that happen a couple years ago.
We had that happen a couple years ago and seemed we could never get rid of them. We would vacuum them up as they appeared. RV might be locked up for a month we come back and find hundreds again. Vacuumed them up. We keep a very clean rig so this did not make sense.
I hung up fly strips in the shower, and on strings in other areas of the rig as well.
Come back next spring and had several on the strips and others dead but that seemed to take care of it after they were cleaned up and removed never had them appear again.
Never really did figure out where or how they got in since it is sealed up well. Just keep after it and you should get rid of them
06 King of the Road 37RLQS
06 Coachman Cross Country 5.9L 300HP 382 DS
03 Jeep Wrangler, 4.0L James, Trina, SMSgt, USAF Ret