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.
Your flower and herb garden is a good place to find insect and flea bite remedies. Basil is a great bite remedy, use either a few drops of essential oil, or crush fresh basil leaves and rub them on bites.