Termiticides: Safe for Indoor Use?

Termites are tough buggers.  Having lived in New Orleans for 10+years, it is hard to understand how any wooden structures are still standing, considering that the city is the perfect climate for them: hot and humid!  I learned without any formal research that the Formosan species of termites does not need any ground contact (so much for termite barriers) to survive; it actually does well in a moist section of your attic or roofing, destroying the wood that holds up your roof!  I renovated a house after Hurricane Katrina and wanting to seal the home well with insulation, I went with a spray foam made from sugar cane.  In hindsight I think spray foam in general was a big mistake!  When I purchased the home in 2009, it had very few signs of termite damage, as all the walls and ceilings were open, and I knew the home (having been built in 1952) just had traditional fiberglass insulation before.  After 7 years of living in it, I had to call the exterminator several times a year for different colonies that invaded parts of the attic, one of which made their way down a wall and into a wood floor!  I think the insulation contained just enough moisture to help them live, and provided great shelter as they munched through the house.  I didn’t notice them at all until I saw a few droppings emerging through the foam, and could actually hear a slight “crinkling” sound in the insulation near the infestation, if the house was completely quiet. 

Many professional exterminators use Termidor, which is a formulation of Fipronil.   Fipronil is used in dog and cat flea medications (Frontline), and used in some outdoor pest applications.  Termidor is labelled as “safe for indoor use”, however, low concentrations are deadly to fish, shrimp, crawfish, honeybees and lizards.  It kills insects by affecting their nervous system, and in other animals, it causes nausea, dizziness, aggression, and interrupts hormones and reproduction.  Fipronil breaks down in sunlight to a chemical that is ten times more toxic, which is fipronil-desulfinyl.  This chemical is more easily absorbed into the skin, as well. (pesticide.org)  Fipronil is also the active ingredient in another termite treatment, Taurus SC.  There is likely gallons of Fipronil in the one house I lived in! 

There are other popular termiticides that are used outdoors, to prevent termites from getting to the precious wood in your home:

  • Imidacloprid is an insecticide that is popular in many other countries besides the US.  It is a sort of synthetic nicotine modeled after natural extracts of the tobacco plant.   It is quite toxic to fish, which is important for homes in areas that runoff to streams, lakes, etc.  It is very persistent in soil, meaning it does not deactivate quickly.  It’s also toxic to some birds, acutely toxic to earthworms, bees, and toxic to some plants.   Imidacloprid is the active ingredient in the flea and tick medication Advantage used for cats, however it is toxic to some cats.  Although it is of low toxicity to humans, why poison our surroundings with something so toxic to nature?  Fuse, Premise and Dominion are products that use imidacloprid to control termites.

  • Chlorfenapyr is a newer insecticide in the class of pyrroles that affect insects’ ability to produce energy.  It works on insects that have become resistant to pyrethroids.  It is supposedly only “moderately” toxic to humans; however, severe poisoning and death have been reported by ingestion, inhalation and exposure to skin.  Spectre 2 SC and Phantom are two products that use chlorfenapyr. 

  • Why put yourself into close contact with a chemical, just to avoid termites or insects?

Fine then–how do I keep termites at bay without using toxic chemicals? Here are some more natural tips:

  • Keep roofs and gutters in good repair, in order to minimize water sources for termites

  • Don’t use mulch next to your foundation; instead, keep it 6-12” away.  This allows air to circulate and doesn't encourage termites to enter the house under cover of mulch. 

  • Stack firewood at least 20 feet away from the house, and raise it off the ground about 8” or more.  This allows air circulation and visual inspection for termite tunnels. 

  • Keep trees and shrubs trimmed so that branches don’t touch your house; also don’t allow dead branches to accumulate on the ground.  Keep large plants away from the foundation, because they can block inspection.   Remember: sunlight and heat are the worst natural enemies of termites and they can’t stay in a hot dry area for very long!

  • For homes that are built above ground on pilings, make sure that termite guards are properly installed on each piling. 

  • Declutter the inside of your house!  I know a landlord whose tenant had stacked newspapers in piles all over the living room floor, which are a favorite termite food.  Now she has to replace the subfloor and some of the joists, which will cost thousands!  Look for telltale piles of sawdust under furniture that has a wooden structure like sofas and beds, and don’t store cardboard boxes or newspapers in your home.  

  • For areas that are prone to underground termites, there is now a stainless steel mesh that can be installed around foundations and underground pipes.  It’s marine grade stainless steel warrantied for 10+ years, called Termi-Mesh

  • Application of Bora-Care or other borate products to unpainted wood is a great deterrent to termites, and borate products can be used in baiting systems.  Boron is a non-toxic element that humans and plants need, in low concentrations.  Therefore, according to the University of Nebraska-Lincoln Cooperative Extension, “Although boric acid is relatively safe to humans and other mammals, it can be harmful if accidentally ingested and must be kept away from food, children and pets. Care must be taken not to breathe in the dust when you apply it. Like other dust formulations, it should be used in places where it will not move around.”  In addition to termite protection, it does not allow molds and fungus to grow. 

  • If you live in an area that is high risk for termites, you will be familiar with swarming season.  During this time, the “alates” or reproductive termites will leave the colony in a brief flight and look for a mate to start another colony.  Usually in late spring, this is when you see swarms of termites surrounding outdoor lights at dusk and after sunset.  It can be a scary sight to homeowners, but don’t let it frighten you!  Turn off outdoor lights on and near your home during swarming season, close drapes or blinds to block light from windows, and make sure you have window screens and weatherstripping installed to keep them out of the house.  If any termites do enter the house, they will die within the day if they do not find moist areas or leaks, so proper maintenance will make sure they don’t start a new colony in your home.  If you do see them entering through a crack or pinhole in the wall, you can use a vacuum to suck them up, ensuring again that there is no moist wood or drywall to sustain them. 

  • If gardening is one of your interests, you may consider planting some of the following around your home, as they have been studied to repel termites: catnip, vetiver grass, and lemongrass. Marigolds are also a favorite of gardeners to deter pests, but they have not been scientifically shown to deter termites.

  • Newer insecticides like Chlorantraniliprole are of very low toxicity to humans, bees and fish, while they cause death to termites by paralysis. 

  • Baiting stations are environmentally safer than pouring chemicals into the ground around your house, because the poison within them is only carried by the worker termites out of the station and into the nest.  However, they can be slow to work and must be checked several times a year, if not monthly, by an exterminator.   If a termite inspection reveals that you have no active infestations in your home, then this may be a good preventative measure.  

Alaska may be the only state that is free from termites, but with some vigilance, they don’t have to take over your home!