Answer: The creatures commonly called sow bug or pillbug or rolypoly or woodlouse are usually attracted to damp areas where there is decaying organic matter. This could be mulch or wood or rotting leaves that are constantly moist, for example. Usually, the best way to stop them is by drying out the area and/or removing the damp material where they hide. If you use an irrigation system and it keeps your mulch constantly wet you could reset it to run less often such as once a week, thus allowing the mulch to dry between waterings.
If they are coming indoors, sealing cracks and crevices should keep them outside as well as help make your home more energy efficient.
I am not familiar with a product called d t powder. There is an insecticide called DDT or Dichloro diphenyl trichloroethane. It was outlawed in the United States in the 1970's due to environmental concerns.
If you feel a chemical control is needed, please contact your local county extension to see what they recommend for use by homeowners today.
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