Master Gardener: How to prevent cat fleas in your yard

Q: Last summer we had a terrible problem with fleas. We have three cats that go outside, but they stay in our yard. What can we do to prevent a flea infestation this year? Should we treat our yard as well as our house?
A: Cat fleas (Ctenocephalides felis) live on both dogs and cats. There are different types of fleas, most are specific to their hosts. For instance, there are fleas that live exclusively on squirrels. Dog fleas resemble cat fleas but are not common in California.  Cat fleas a