There are several types of termites, but the Eastern subterranean termite (Reticulitermes Flavipes) is the most common and widely distributed termite in North America, according to the Pro-Line Pest Control website. Several environmental factors serve to attract termites. The insects seek out locations that provide for their basic needs: food, water, warmth and shelter.

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Be on the lookout for termites if you have a wooden trellis.

Food

Termites consume materials made of cellulose. These include wood, wood products, cardboard and paper. You should keep wood on your home out of contact with the soil, leaving a gap of 6 inches between the ground and any wood used in construction. Never stack wood near your home or outbuilding. Conscientiously remove any construction debris and old stumps, and prevent contact between wooden trellises and your house. Use pressure treated lumber, naturally resistant woods such as redwood or alternative materials instead of wood for construction to avoid attracting these pests.

Habitat

Subterranean termites are attracted to locations that offer not only a food source, but soil in which they can tunnel to their chosen food source. Tunneling protects the termites from predators, and the insects will tunnel hundreds of feet to reach a feeding site, according to the Ohio State University Extension. Termites may live in the soil below the frost line and also have a secondary colony above ground.

Moisture

Termites require moisture not only to live, but to use in forming mud tubes. These tubes bridge the distance between their tunnels and their food source, providing cover where there is open ground and on surfaces where they are unable to tunnel. The tubes help keep the termites hydrated and offer protection from predators. You should act to divert water away from your home and outbuildings, including grading the soil away from their foundations to encourage drainage, according to the Ohio State University Extension. You should also remove any plants growing near the foundation of your home. Plants offer a source of moisture and can cover signs of damage or tunnels.

Warmth

Termites aren't usually very active in winter, but access to a heated area allows the insects to continue to feed through cold weather months. Wood mulch around the foundation of your home may serve as a source of food and attract termites toward your home's foundation, where the insects can find their way inside. Termites can enter through cracks as small as .03 of an inch, according to the University of Nebraska-Lincoln Extension.