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.
Holes tend to be 2-3 inches wide and smooth from repeated use. Rats are secretive and rarely seen during the day. If you see them during daylight hours, it means you have a lot of rats on the premises. Drawing of their burrow system can be seen below. Photo at right shows a Norwary rat hole. Note the 6 ruler above.