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.
Repelling harmful insects and pests from your garden can be done naturally with companion and border planting or by making your own insect and rodent sprays. Natural remedies are inexpensive and keep your soil healthy. Leftovers from the kitchen can also be helpful in controlling pests.