I have been fighting these damn things for three years since I brought them from an infested house. By cleaning under the cages at night with a small flashlight and brush and dustpan I can keep them under control by squishing them and the larvae but I have started using a natural pesticide spray called Bioganic. It contains thyme oil, clove oil, sesame oil, water, wintergreen oil, soy oil and lecithin to keep it emulsified. I put it in a small spray bottle and spray it along the edges where there problems. It seems to be helping as I haven't seen any more larvae where I have sprayed. A small shop vac is also helpful for cleaning up the debris. Dump the container each day to a trash bag. Also when cleaning, if the cage is on a stand with wheels roll it away a little and clean where the wheels were. The beetles eat the crushed bits of food under the wheels. Take the cage off the stand and clean that, too. My sympathies to your relatives. If the infestation is bad you'd better clean your shoes after leaving their house. Carol J. Owens Ferret Friends, Inc. Tucson AZ [Posted in FML 6061]