Does Dark Brown Premium Mulch Attract Ants?

The Ants Go Marching

• Although it's reasonable to think that carpenter ants would see shredded hardwood mulch as a convenient buffet, these ants don't actually use wood as a food source. They are looking for solid chunks of wood -- old stumps -- or the posts and studs that hold up your home -- in which to build nests. Common household and lawn ants that may live in under mulch are not harmful to your plants or the structure of your home. Ants aerate soil with their tunnels and underground nests, eat other insects and enrich the soil with the bits of food and other material that they bring into the soil. The insects are attracted to the soil under mulch because it is less frequently disturbed, retains moisture and is warmer than surrounding soil. Consistently raking down any ant hills and dousing them with the hose can cause problem colonies to relocate.

Fiery Exception

• Gardeners living in warm climates may find that fire ants, which can sting and harm plants and produce, make a home in mulched areas -- premium or not -- when conditions are dry or cold, for the same reasons as less harmful ants -- access to moisture and warmth. Fire ants typically create large mounds that also detract from the look of the landscaping. A bait product labeled for fire ant control is recommended when fire ants are a problem. Raking mounds or dousing fire ants with water or a chemical drench can be hazardous as the ants are extremely aggressive when disturbed.

Termite Toss-Up

• Antlike termites do, however, feed on wood and may feed on the wood and cellulose in your premium mulch but only if they were already present under the mulched area. Laying mulch won't draw termites to the area and is unlikely to import them to your yard, according to the Iowa State University Extension. Termites prefer material, like cardboard, that has more easily available cellulose. However, if you have a termite infestation, rethink using any type of mulch near a structure. No matter the material, mulch makes the soil underneath a more comfortable home for the damaging insects.

Neatness Counts

• Although common ants aren't considered harmful, they can make the occasional, annoying foray into your home looking for food and water. Keeping mulch several inches back from your home's foundation and any contact with door or window sills discourages insect travel into your home. Maintaining the mulch layer at only 2 to 3 inches deep also decreases the amount of heat and water it holds in the ground, while still looking good and benefiting plant roots. You might also consider a switch to a different kind of mulch if you're squeamish about ants. Cedar mulch, made with Thuja species, repels odorous household ants and Argentinian ants, as well as termites, cockroaches and carpet beetles, according to Washington State University horticulturalist Dr. Linda Chalker-Scott.