In such cases the weeps consist of small-diameter plastic, clay or metal pipes extending through the wall to a layer of porous backfill. Typically, weeps are arranged to direct water which may have entered an assembly from outside back to the outside.
A few of several safe household chemicals to use are vinegar, dishwashing soap and rubbing alcohol, according to an Oregon State University Extension Service publication called Using Home Remedies to Control Garden Pests, (EC 1586). The publication, complete with photos, is available free of charge online.
Two of the very best choices for sensible pest control are horticultural oil and insecticidal soap. They control more of the pests that trouble our landscape plants, garden plants and house plants than an arsenal of synthetic pesticides and do it with minimal danger to us, our pets and the earth.