The best method of subterranean termite control is to avoid water accumulation near the foundation of the home. Prevent subterranean termite access by diverting water away with properly functioning downspouts, gutters and splash blocks. Store firewood at least 20 feet away from the home, and keep mulch at least 15 inches from the foundation. Indoors, homeowners should reduce humidity through proper ventilation of crawl spaces, attics and basements to avoid attracting subterranean termite swarms.