Types of Ants

In my previous post I covered general information on ants – those minuscule little pests that raid the sugar bowl. This post will cover specific types of ants, including their appearance, preferred foods, nesting and mating habits and treatment recommendations.

As a reminder, the best treatment for any ant problem is to find the nest and treat it chemically – you must kill the queen ant for the problem to be completely eradicated. If you can’t locate the nests, then an insecticide spray should be used around the perimeter of your home, as well as appropriate baits and treatments indoors.

Thief Ants

Thief Ant

Thief ants tend to be the most common household invader of the ant kind. There are called thief ants because they often nest near other ant colonies and steal their larvae for food. They resemble Pharaoh ants (see below) in appearance, so you may need a pest control specialist to identify them correctly. Generally, however, they are yellow to light brown in color and the worker ants are approximately 1/20 of an inch long. Another distinct characteristic is their tendency to curl up when dead. Their mating season is July through September.

Thief ants are often called grease ants because their foods of choice are considered greasy, such as meats, cheese, peanut butter and nuts. Don’t let that fool you though because these pests will also eat sweets.  Due to their small size, they can invade almost any food container, so these are the ones you often find actually in the sugar bowl or peanut butter jar.

Thief ants usually invade the home in mid to late summer months when food is scarce outdoors. They nest in soil and rotting wood, but also indoors in small spaces such as wall voids, under counters and behind baseboards.  It’s important to note, however, that thief ant nests are extremely difficult to locate, so it’s best to treat the perimeter of your home and grease-feeding ant baits indoors.

Odorous House Ants

Odorous House Ant

When killed by crushing, these ants give off an unpleasant order, hence the name. They are one of the more common household invaders. They are brown to dark brown in color and about 1/10 of an inch long. Odorous ants prefer sweets as their food source, as well as insects and the honeydew insects produce.

Odorous ants nest in the soil, typically near or under objects laying on the ground such as rocks, boards, firewood, the base of patios or mulching plastic. They might also nest inside the home in wall voids or under the floor. Their mating season is during June and July.

The recommended treatment is to locate and chemically treat the nest. If you can find the nests, use a spray around the perimeter of your home and install bait traps indoors that are designed for ants that eat sweet foods.

Pavement Ants

Pavement Ant

Another common indoor pest, pavement ants are reddish brown to black in color and the workers are about 1/8 of an inch long. They will eat practically anything, including meats, pet food, sweets, bread, nuts and other insects.

Pavement ants get their name from where they prefer to nest – in the soil under sidewalks, driveways, stones, and under homes build on concrete slabs. They enter the home through cracks in the concrete. Mating occurs mostly May through July. However, if the nest is under the foundation of the home, they may mate indoors during the winter.

Baiting is the most effective if the nests are under the home. Use baits made for grease-feeding ants.

Acrobat Ants

Acrobat Ant

Acrobat ants are called thus because, when disturbed, they raise their heart-shaped abdomen over the middle of their body in protest. They are yellowish-brown to black in color and the workers are about 1/8 of an inch in length. They eat everything from sweets to meats, including other insects.

Acrobat ants prefer dead or rotting wood as their nesting site, although they have been found to nest in the soil under stones and in wall voids or window frames in the home (especially if the wood is rotting). They mate from July to September.

Remove any dead or rotted wood from your home or yard. Even if you don’t have a problem with acrobat ants yet, this is generally a good policy. If the wood is infested, you need to destroy it. While you can use an insecticide to treat wood, you don’t want to do so on firewood b/c that can cause a fire when burned later. Indoor nests should be treated with an insecticidal dust as described in my last post.

Field Ants
Field ants are black, brown, red or a combination of the three. They have both major and minor workers that range in size from 1/8 to 1/4 inch. Their favorite foods are household sweets and insect honeydew, though they are also known to each both dead and alive insects.

Field ants do not nest indoors. Instead, they build mounds of grain-like substance in the soil, out in the open and often times rather large. They mate from July to September. Treatment of outdoor nests is the best defense.

Pharaoh Ants
Pharaoh ants were likely imported here from tropical Africa conditions.  Due to this place of origin, they prefer warmer conditions, which means they mostly nest indoors – usually in hospitals, nursing homes, schools and apartment buildings. If you see a lot of ants during cold winter months, then they are likely pharaoh ants. Their nests are usually in small spaces, such as cracks, crevices and other small and hard to get to voids. The nests are usually in dark, warm locations near moisture (bathrooms and kitchens).

Pharaoh ants are light yellow to red in color, but the abdomen (back portion) is often darker than the rest of the body. Worker ants are approximately 1/16 inch long. The antennae are usually longer than most other ants. It’s important to have them identified by an expert.

Pharaoh ants prefer greasy and fatty foods, though they will eat a variety of other things including sweets, dead insects, toothpaste, soap and other items you don’t often see ants foraging. They are most commonly found in kitchens and bathrooms because they find water there.

Pharaoh ants are virtually impossible to eliminate on your own – you will likely need a pest control expert to do the job. Insecticides actually cause them to bud (move some of the larvae to a new location) and create new colonies, so baits are your best option for control, but there aren’t many effective baits available to the general public – usually only commercial pest control companies have access to them.

Carpenter Ants
Carpenter ants are usually some of the largest you’ll find, with workers ranging in size from 3/16 to 1/2 an inch in length (with both major and minor workers). They are usually black or red and black.

Contrary to common belief, carpenter ants don’t eat wood, but chew it into sawdust as they create tunnels within the wood. The actually prefer other insects for food, and will also eat insect honeydew, syrup, honey, sugar and jelly.

They nest in moist or rotting wood of any kind. Outdoors this could mean trees, firewood or flower bed boarders. Indoors this usually means behind walls near water pipes, behind bathroom tiles, near dishwashers, under roofing, in attic beams and under subflooring. They also like hollow indoor spaces such as curtain rods, door and window frames. Insulation is also a nesting location of choice due to the tunnel-like structure it provides.

Carpenter ants mate between April and June and sometimes earlier indoors if it’s warm enough. Chemical treatment of the nest and removing and replacing damaged wood is crucial to elimination, as is getting rid of any moisture problems in the home. Apply baits to location where you notice activity.