Combine an IPM program with a few of these DIY deterrents and repellents, and you can come up with a successful comprehensive plan to get rid of mice naturally. How Poison Works: Most rodenticides on the market today are anti-coagulants.
Rats are rodents that can spread disease, contaminate food and chew up property. Rats burrow in the ground, forming tunnels with one main opening and one or two exits. The 2- to 3-inch wide entrance hole is usually found under a covering like a low plant, mulch or debris. Before closing up burrows, the rats must be eliminated or they will just re-open the holes.
A quarter is just under an inch in diameter (0.96 inches). Not all rats can fit through a hole the size of a quarter. Large rats and overweight rats are too big. But some rats are small enough to fit through -- especially juvenile rats.