Q. I have noticed a lot of rat activity in my garden this spring – more than I’ve ever seen! What can I do to at least keep them out of my house?
The heavier rains earlier this year have caused the local vegetation to thrive, including the weeds. As if that weren’t bad enough, now we have an explosion in the rat population.
The biggest concern with rats is indeed keeping them out of your house. They are awful in the garden but can do far more damage to your home. They can also get inside your car where they will chew through wires and hoses.
Removing shelter and food sources are the first steps in dealing with a rat problem. Start with cleaning out the garage since they can easily move into the house from there. Be ruthless when decluttering to remove any sources of nesting material or food. (I like to watch a few episodes of “Hoarders” for motivation.) Look for shredded materials, piles of empty snail shells (they love to eat snails), droppings, and greasy marks along the base of your walls. If you find any of these, you may already have rats living in your garage.
If you must store pet food in the garage, keep it in heavy plastic or metal containers with secure lids. Remove food bowls once your pets have been fed. Replace cardboard boxes with heavyweight plastic totes with secure lids.
Snap traps are the most economical, environmentally friendly, and effective way to kill rats indoors. Start with 10-15 traps and place them along the walls. Do not set them but spread some peanut butter on the trigger to make the rats comfortable with their presence. Do this for a few nights, perhaps adding dog kibble to the peanut butter. If possible, use glue or wire to firmly attach the bait to the trap. This will force the rat to work harder for his snack. After a few nights, set all the traps (with bait firmly attached). Don’t forget to check on them the next morning. Hopefully, you will have caught at least a few. Wear gloves and dispose of the dead rat by burying it or placing it in a plastic bag and throwing it in the trash. I have also left them out in an open field across the street so the crows can enjoy them for breakfast. Do not compost!
After savoring your victory (hopefully!), double-check for any openings where rats may reenter. Install door sweeps, fill any smaller holes with steel wool, and place galvanized hardware cloth over any vent holes. You may want to periodically place traps to catch any stragglers, but don’t forget to check them daily.
Keeping rats out of your car is a more challenging proposition. Don’t store any food in your car since that will attract rodents. Check under your hood frequently and look for any signs of nesting activity (and check your oil level while you’re at it). Some people swear by mothballs, soap, and other scented repellents. They may work for a while, but rats become accustomed to them so their effectiveness may be limited.
Los Angeles County
mglosangeleshelpline@ucdavis.edu; 626-586-1988; http://celosangeles.ucanr.edu/UC_Master_Gardener_Program/
Orange County
ucceocmghotline@ucanr.edu; http://mgorange.ucanr.edu/
Riverside County
anrmgriverside@ucanr.edu; https://ucanr.edu/sites/RiversideMG/
San Bernardino County
mgsanbern@ucanr.edu; 909-387-2182; http://mgsb.ucanr.edu