Officers say a third child, a young girl, has been taken to UC Davis Medical Center with serious injuries.
Sgt. R.L. Davis says it appears that the victims were shot.
Sheriff's department spokeswoman Sharon Chow says the department received a 911 call Monday morning from someone who said there were "people bleeding" at a home on Rooster Way. An officer responded and found the bodies.
Davis says officers are checking with neighbors to see if anyone saw or heard anything unusual.