WildCare -- Wildlife Solutions Service
Do I Hear Gnawing?
Rodents breed all year long, but the peak season for rodent nesting begins in February. This year-round breeding cycle makes sense. Rodents are the dietary staple of almost every land-based carnivore, so they have to be prolific. If one is at the low end of the food chain, a good biological strategy is to breed early and often.
Two species of rats have plagued (pun intended!) people for thousands of years. They came here with our European ancestors. These introduced rodents joined our ancestors in cities and suburbs. Marin County's only native rat, the Dusky-footed Woodrat, shuns our homes, and still prefers its laboriously-engineered stick nests out in the woods.
The common names of our two non-natives give clues to what to expect from them. The Norway Rat (Rattus norvegicus), is also known as the Sewer Rat, and is a large rat that prefers to live near water in underground burrows. The most common rat around Marin homes is the arboreal Black Rat (Rattus rattus) aka the Roof Rat. It likes trees and attics, although there is some overlap in the two rats' habitats. The House Mouse (Mus muscalus) is the mouse most likely to invade your cupboard.
A rodent's teeth continue to grow throughout its life. Gnawing on hard objects such as wood and bone is essential to maintaining a rodent's teeth. This gnawing behavior is the primary cause of damage to buildings. Rats can make use of openings as small as 1/4", and enlarge them enough to allow access for squirrels, raccoons, skunks and other species of wildlife. That is when rodents can go from being a carnivore's delicacy to a home-owner's nightmare.
How to Control Rodents Humanely
The best method of rodent control is prevention. Rodents tend to set up camp in our homes and businesses when food and space are made available to them.
Learn more about rats to help control them
Black Rats may establish nests in bamboo, ivy, palm trees, yucca, pampas grass, honeysuckle, blackberries, cypress, jasmine, juniper and other heavy shrubbery or thickly matted plants. Wood and lumber piles, storage boxes and sheds frequently provide shelter and safety.
Norway Rats may live in burrows along outside walls of homes, holes under shrubs or vegetation, and under the edges of sidewalks or patios. These nocturnal, opportunistic foragers are attracted to pet food, fallen bird seed from feeders, and fruit fallen from trees.
Garden problems almost always involve food and water sources. In most cases, solutions to these situations are often very simple. Learning what is attracting rodents and eliminating access to food will help solve the problems.
Rats and Rodenticides
Rodenticides, even though they are available for purchase everywhere, are dangerous poisons that can cause secondary poisoning in the beneficial species that prey upon rats. Hawks, owls, bobcats, raccoons, skunks and other carnivores all depend on rodents for food. These wild predators, and even pet cats and dogs, are in danger of being poisoned by these toxic, unnecessary products. Rodenticides are also ineffective, because rats breed too quickly to be managed by poisoning. Click to learn more about the dangers of rodenticides to hawks, owls, foxes and other rodent-eating predators.
Killing rats outdoors rarely solves a rodent problem, because if the attractions remain, more rats will take the place of the killed rodents. It is not possible to eliminate all rats from the environment, but they can be controlled. Keeping your home and garden unfriendly to rats will allow their natural predators to keep rodent population numbers in balance. As described above, excluding rodents from your building, sealing their access points, and eliminating any rats trapped inside are the only long-term solutions.
Rats and Traps
Glue traps, like poisons, kill indiscriminately and are incredibly cruel and inhumane means of death. Small birds, reptiles and non-target mammals are all attracted to the traps for the same reason the rats are.Once stuck to the glue trap, the animal slowly dies of dehydration and starvation, often injuring itself with struggles to escape the sticky trap. Learn more about why you should NEVER use glue traps here...
Snap traps, used correctly as part of a professional exclusion program, deliver a fast, humane death, and are WildCare's recommended method for use indoors if necessary. Like glue traps, snap traps used outdoors are dangerous to many species of non-target birds and animals, especially young ones. Rats establish runways along walls, and are very wary of new things in their environment. Dead rats should be removed from traps immediately, because any live rats will avoid an area where they see another rat has been killed.
Exclude the Intruders
Many wild animals will take advantage of a rodent's opening in a warm, dry house. To protect your home, the most humane option is also the best one for your resale value. Clean up and repair your property so rodents can't get in. Now is a good time to do it – before you have a problem.
WildCare receives hundreds of calls on our Living With Wildlife Hotline from people looking for advice on how to rid themselves of rodents. Our best answer is always the same: exclude them from your home and remove the food source that is attracting them.
If you have questions or problems about damage in or around your home, WildCare Solutions service can help. Call 415-456-SAVE (7283).