Odorous House Ant
Encyclopedia
Tapinoma sessile is a species
of ant
that goes by the common names odorous house ant, stink ant, and coconut ant.
, and other insect
s. Indoors they will colonize near heat sources or in insulation
. In hot and dry situations, nests have been found in house plants and even in the lids of toilets. Outdoors they tend to colonize under rocks and exposed soil
. They appear, however, to form colonies virtually anywhere, in a variety of conditions. They can trail extensive distances (though their trails are rarely longer than 50 feet), usually along landscape edges. Colonies range in size from 100-10,000, and house several queens
(as many as 200, in some instances). They are non-aggressive. While queens can lay as many as 20-30 eggs in single day, they lay only 1-2 (or less) eggs per day on average over long periods of time. Typical time to adult phase of development is 34–38 days. It is believed that queens and male ants are only produced in larger colonies.
In experiments where T. sessile workers were confined in an area without a queen, egg-laying (by the workers) was observed, though the workers destroyed any prepupa that emerged from the eggs.http://www.archive.org/stream/ants_02617/ants_02617_djvu.txt
Odorous house ants have been observed collecting honeydew to feed on from aphid
s, scale insect
s, and membracid
s.
They appear to be more likely to invade homes after rain (which washes away the honeydew they collect).
Odorous house ants appear to be highly tolerant of other ants, with compound nests consisting of multiple ant species (including T. sessile) having been observed.
Little is known about the lifespan of the ant, though it has been shown that queens can live at least 8 months (and probably much longer), workers at least a few months (and show every indication of living as long as queens), and males appear to live only approximately a week.
The odorous house ant is very tough, and injured workers have been observed to continue living and working with little hindrance. Some queens with crushed abdomens could still lay eggs, and there are documented instances of T. sessile queens surviving without food or water for over two months. They also appear highly tolerant to heat and cold. These ants are tough to remove from the body and leave an odorous smell as well.
Isobrachium myrmecophilum (a small wasp) appears to parasitize odorous house ants.
Some birds and toads will also eat odorous house ants on occasion.
the ants produce when crushed, which is very similar to the pungent odor of a coconut
.
foam
or caulk, especially those that are near the ground. Firewood
, rocks and other materials should not be stored next to a home because it encourages nest building. People should be on the lookout for these ants in late winter and early spring (particularly after rain), as this is when they most commonly appear.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
that goes by the common names odorous house ant, stink ant, and coconut ant.
Habits
This species is a scavenger/predator ant that will eat most household foods, especially those that contain sugarSugar
Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...
, and other insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s. Indoors they will colonize near heat sources or in insulation
Thermal insulation
Thermal insulation is the reduction of the effects of the various processes of heat transfer between objects in thermal contact or in range of radiative influence. Heat transfer is the transfer of thermal energy between objects of differing temperature...
. In hot and dry situations, nests have been found in house plants and even in the lids of toilets. Outdoors they tend to colonize under rocks and exposed soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
. They appear, however, to form colonies virtually anywhere, in a variety of conditions. They can trail extensive distances (though their trails are rarely longer than 50 feet), usually along landscape edges. Colonies range in size from 100-10,000, and house several queens
Eusociality
Eusociality is a term used for the highest level of social organization in a hierarchical classification....
(as many as 200, in some instances). They are non-aggressive. While queens can lay as many as 20-30 eggs in single day, they lay only 1-2 (or less) eggs per day on average over long periods of time. Typical time to adult phase of development is 34–38 days. It is believed that queens and male ants are only produced in larger colonies.
In experiments where T. sessile workers were confined in an area without a queen, egg-laying (by the workers) was observed, though the workers destroyed any prepupa that emerged from the eggs.http://www.archive.org/stream/ants_02617/ants_02617_djvu.txt
Odorous house ants have been observed collecting honeydew to feed on from aphid
Aphid
Aphids, also known as plant lice and in Britain and the Commonwealth as greenflies, blackflies or whiteflies, are small sap sucking insects, and members of the superfamily Aphidoidea. Aphids are among the most destructive insect pests on cultivated plants in temperate regions...
s, scale insect
Scale insect
The scale insects are small insects of the order Hemiptera, generally classified as the superfamily Coccoidea. There are about 8,000 species of scale insects.-Ecology:...
s, and membracid
Treehopper
Treehoppers and thorn bugs are members of the family Membracidae, a group of insects related to the cicadas and the leafhoppers. There are about 3,200 known species of treehoppers in over 600 genera...
s.
They appear to be more likely to invade homes after rain (which washes away the honeydew they collect).
Odorous house ants appear to be highly tolerant of other ants, with compound nests consisting of multiple ant species (including T. sessile) having been observed.
Description
They range in colour from brown to black and range in length from 1/16 to 1/8 inches (1.5–3.2 mm). Their antennae have 12 segments.Little is known about the lifespan of the ant, though it has been shown that queens can live at least 8 months (and probably much longer), workers at least a few months (and show every indication of living as long as queens), and males appear to live only approximately a week.
The odorous house ant is very tough, and injured workers have been observed to continue living and working with little hindrance. Some queens with crushed abdomens could still lay eggs, and there are documented instances of T. sessile queens surviving without food or water for over two months. They also appear highly tolerant to heat and cold. These ants are tough to remove from the body and leave an odorous smell as well.
Predators and parasites
Wheeler (1916) mentions Bothriomyrmex dimmocki as a potential parasite of oderous house ant colonies (suggesting that B. dimmocki queens invade and replace T. sessile queens).Isobrachium myrmecophilum (a small wasp) appears to parasitize odorous house ants.
Some birds and toads will also eat odorous house ants on occasion.
Origin of common names
The common names "odorous house ant" and "coconut ant" come from the odorOdor
An odor or odour is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also commonly called scents, which can refer to both pleasant and unpleasant odors...
the ants produce when crushed, which is very similar to the pungent odor of a coconut
Coconut
The coconut palm, Cocos nucifera, is a member of the family Arecaceae . It is the only accepted species in the genus Cocos. The term coconut can refer to the entire coconut palm, the seed, or the fruit, which is not a botanical nut. The spelling cocoanut is an old-fashioned form of the word...
.
Control
These ants are not hard to control, and most ant killers will solve problems, especially if controlled as soon as the problem is noticed. At this point, they could be put under control in just a few days. However, the longer someone waits, the larger the population is and the longer it will take to control the situation, possibly a few weeks. Standing water should be eliminated, as odorous house ants are attracted to moisture. Plants should be trimmed back so they cannot be used to get inside. Cracks, holes and joints should be sealed with polyurethanePolyurethane
A polyurethane is any polymer composed of a chain of organic units joined by carbamate links. Polyurethane polymers are formed through step-growth polymerization, by reacting a monomer with another monomer in the presence of a catalyst.Polyurethanes are...
foam
Foam
-Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...
or caulk, especially those that are near the ground. Firewood
Firewood
Firewood is any wood-like material that is gathered and used for fuel. Generally, firewood is not highly processed and is in some sort of recognizable log or branch form....
, rocks and other materials should not be stored next to a home because it encourages nest building. People should be on the lookout for these ants in late winter and early spring (particularly after rain), as this is when they most commonly appear.
Sources
- The Biology Of Tapinoma Sessile Say, An Important House-Infesting Ant (Written by M.R. Smith, published 1928 in the Annals of the Entomological Society of America)
- National Pest Management Association Fact Sheet from the NPMA, featuring data on habits and habitat as well as photos