Question I baited rats in the ceiling in January this year and have had lice scooting around my body for months. I am unable to remove the nest or caucus's as it a very small gap. I have only ever seen one that got into my IPad so was against a white lit screen. Now they are nipping occasionally and didn't at first. I have sprayed,washed,cleaned etc over and over. My main spots where they jump on me are in the lounge room and in bed. I have new leather lounge chairs, new carpet, and spray every time I go into these rooms. I also spray my clothes and bed linen with a eucalyptus dust mite spray and spray my hair with it as well as aerogard personal mosquito and midgie spray. How long do you think they will last without the rat blood. I also have no pets so they aren't an issue. I live in Brisbane in Australia.
I think you are referring to rat mites, not lice (see http://www.livingwithbugs.com/bird_mites.html for info about these mites). These mites sometimes leave the nest of their host animal when the nest is abandoned or the host is dead. The mites will bite but will not set up a long-term infestation. The best option is to just clean (no insecticides) until the mites die off usually in a fairly short time. I can't be more specific than that but the insecticides probably are not doing any good.
I can answer questions about the control of pest insects, spiders, mites and related arthropods. These household pests include termites, carpenter ants, powderpost beetles, nuisance ants, bed bugs, cockroaches, fleas, wasps, and many others. I can also answer questions about using pesticides and other pest control tools such as baits and traps.
I am a retired university extension entomologist. I've taught and conducted research in urban and agricultural entomology. I've published over 70 extension publications, 20 research publications and several books about insects.