|Nutmeg Mannikins flock to a feeder filled with sunflower and millet. Photo by J.J. Meyer|
The best way to control rats is to keep birdseed off the ground. If you buy good quality birdseed, the birds will consume it all. There will be nothing on the ground for the rats. The junk you get at big box stores has a high percentage of grain filler that none of the birds in our area eat. The grain collects on the ground and attracts rats. Black oil sunflower seeds, although more expensive, will be entirely consumed by the birds.
My feeder in the photo has both black oil sunflower and millet. The perching birds love sunflower and kick the millet to the ground where the sparrows, towhees, mourning doves and other ground feeders clean it up. By sunset, there is nothing on the ground left for the rats. I also bring my feeders inside at night. This method works for me.
If maintaining a birdfeeder is a problem, install a fountain or a birdbath and plant lots of native California plants. You'll get a wide variety of bird species in your yard.
But please, don't use poison to control rats. It kills our beautiful hawks and owls.