Moisture is also critical as all animals need water to survive. Insects, however, are particularly sensitive to drying out so most prefer someplace moist or humid. Puddles of water is what jumps to most people’s minds when thinking about moisture. But for insects, it’s the water trapped under heavy ground covering plants next to the foundation or the moisture associated with a pile of bricks, boards, or debris by the foundation. Once harboring and thriving in such locations so close to the building, ants, crickets, spiders, and other pests are more likely to find their way inside.
Take a look around the exterior of the building, especially near the foundation. Ground-covering vegetation (e.g., ivy, pachysandra, monkey grass) should be avoided near a building; instead, plant shrubs and flowers spaced apart to help reduce moisture. Also, mulch should not be more than 2 inches thick. Any more than that holds so much moisture that many pests actually prefer it.
When planting trees or shrubs, take into account their mature growth size. If a mature tree can span 30 feet in canopy then don’t plant it 12 feet from the building when it is a sapling. Otherwise the branches lie against walls or on the roof and hold moisture. Such branches also provide a path directly onto the building. Tree branches should be kept cut at least 6 feet from the roof — rats can jump that far. For shrubs, plant them far enough away from the building so that when full grown, you don’t have to keep pruning the branches back from the building. Adjust the irrigation system to avoid over watering and direct it away from the foundation.
Food is something that motivates all living things. Different pests require different types of foods. Flies are partial to garbage in the dumpster area as are rats and mice. Disposing of trash in plastic trash bags reduces odor and regular cleaning of dumpster and trash areas also limits flies. It is also helpful to locate trash areas as far from a building as possible. Both of these are extremely important during late summer when yellowjackets are most abundant.
Ants like to forage on plants with aphids — aphids exude a sweet substance as they feed called honeydew and worker ants need honeydew for energy. If a building has aphid-prone plants and trees next to it, it is more likely to become infested by ants. Changing such plants to those less attractive to aphids means fewer ants.