Eco PCO ACU may be applied if pets are in the house, however we would recommend refraining from spraying any insecticides while pets are in the same room. You want to wait until applications are dry before allowing pets to re-enter the area. Eco PCO ACU is not, however, an appropriate treatment for fleas. We recommend our Indoor Flea Kit for your situation. You want to keep pets out of the treatment area until the application is complete and dry.
A very gently product for use on the cats themselves would be Greenway Formula 7 Dog and Cat Flea and Tick Spray.
The System III should be compatible with any type of aerosol including the Eco PCO ACU.
Onslaught is a great product for chigger control. Treatments for chiggers should begin in April/May and could need to continue through the summer as new chiggers move into the area. Treating the entire lawn is of little benefit because chiggers avoid direct sunlight and normally will not infest areas that are mowed or otherwise well maintained. Focus treatment on the unkempt areas of the lawn and lawn edge. You can also use Onslaught to do a barrier treatment around the outside of your home and around your baseboards indoors to stop pests from moving indoors.
While the Eco PCO ACU does not have a residual, it may exhibit some repellent properties temporarily with the initial spray. We would recommend letting any treated surfaces dry completely before spraying the Phantom in the same areas of the home.