I live near a creek. I do not have river rats but my neighbors have had them. Wanting to prevent them in my house, I hired Robert Scott, owner of Avexium, a highly skilled and experienced rodent control expert. He applied a roof exclusion which is a metal strip at the roofline which block rats and other rodents from entering the attic. Robert applied wire mesh to a wall of lattice-designed bricks on the wall of my attached utility room. He also plugged all holes with mesh and an exclusion-type caulk to keep animals from entering my home through those tiny entrance-ways. If that wasn't enough, Robert's previous experience as a general contractor gives him a grounding in house construction unlike his competitors. After completing the rodent exclusion work, he added a few wooden supports, purlins, inside my attic roof which had never been placed in the attic above a finished carport. I found Robert to be an exceptionally hard-working, courteous gentleman with a work-ethic that won't quit until the job is done in an excellent fashion. I can't recommend him highly enough!!!