Sewer rats living in your RV’s gray water tank? Sewer flies breeding in your black water tank? It may sound like an urban legend or the stuff of nightmares, but unfortunately, these things can happen if you’re not careful. So, what do you do to maintain RV sanitation?

As the name implies, sewer flies (or drain flies) live in the sewer system, so they can have a clear path to your RV if you neglect to keep your gray water tank closed while in an RV park.

In this video with RV Travel’s Chuck Woodbury, you’ll hear about a couple that heard thumping noises in the middle of the night after making this common RV waste management mistake. It turned out that the couple wasn’t alone in their RV — a sewer rat was living with them! You’ll also watch Chuck tell the story of a woman who watched in horror as sewer flies emerged from her toilet after making the same mistake.

Don’t be left vulnerable: watch our video to learn how to keep critters out of your holding tank sewage system and subscribe to Drain Master’s Youtube channel for even more RV living tips!