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.
1 Roof rats build nests in attics, trees, and overgrown shrubbery or vines. Roof rats rarely dig burrows for living quarters if off-the-ground sites exist.  Norway rats prefer to nest at or under ground level, and in the lower floors of buildings.