Bests & Worsts Reviews from Amazon

I've used five cans of this so far. It works, but if the rats are determined they will gnaw through it. The simple answer is to embed hardware cloth in the foam. Here's how: 1. Cut a patch of hardware cloth to snugly fill your gap. 2. Leave a tab on one side to hold the patch in place with duct tape. 3. Bend the tab, tape up the patch, then slowly spray this foam sideways across the face of your patch. 4. If you are spraying overhead, spray right through the patch so the foam grows on top of the patch. 5. Remember that this foam expands a LOT, including right through the hardware cloth I filled a 4-inch gap around a bent pipe using this technique. The foam grew several inches above and below the patch. If rats start to gnaw through the foam, they will encounter the screen and stop. I've battled city rats who could get through 3/4 inch plywood reinforced with hardware cloth. This foam will not stop them, even if reinforced. But If yours are the more opportunistic country rats like the ones I battle these days, this foam is great.