Big-Headed Ants

The Big-Headed Ant


By Sarefo – Own work, CC BY-SA 3.0, 

Big-headed ants (Pheidole megacephala) are an invasive species of ants that often displace other ants, such as fire ants and white-footed ants. They are quite common in the US. Belonging to the family Formicidae, this ant is known as the coastal brown ant in Australia. These ants have disproportionately large heads, and can often infest homes and other buildings.


  • Disproportionately large head (of the major worker ants)
  • Reddish-brown body
  • Some species of this ant can also be yellowish in color.
  • Body is around 1/4th inch in size

Appearance, Behavior, and Signs

Big-headed ants pose no structural threat to your house, and neither do they have a painful bite. But they can be a nuisance because they feed on garbage and other items. They can leave ‘dirt piles’ scattered across the house, as they forage around the area. They can also feed on houseplants, and cause them to wilt.

  • These ants usually nest in the soil and may enter homes in search of food
  • They are also found beneath logs, rocks and rotting wood
  • They establish trails from the nest to sources of food and water
  • Several other species of the big-headed ant are known to make ‘supercolonies’ – nests that are massive and have hundreds of sub colonies
  • Their colonies are easy to spot as there will be a lot of displaced sand around it
  • These ants are omnivores that will eat almost everything – from dead insects to garbage
  • They are especially partial to sweet honeydew produced by aphids
  • A sure sign that you have a big headed ant infestation is the presence of dirt piles around the house – these are due to the ants foraging for food
  • The major worker ants have an oblong, abnormally large head while the other workers have a smaller head
  • These ants often gather in the kitchen, as they are attracted to food high in sugar and protein
  • Big-headed ants are often seen crawling up along the sides of walls
  • They are commonly found near patios, as there is loose soil there
  • They do not have a painful bite and are generally non-aggressive


Big-headed ants enter homes in search of food. They can enter through cracks in walls and windows, or can simply climb up from the patio or backyard. If there are fruit plants or trees around your house that have branches touching the building, these ants can easily walk and enter. They are also found in the loose soil near the foundation of the building. They main target is the kitchen – so if you have an infestation you can be sure that they’ll be gathered in the kitchen.

Florida is especially known to have troubles with big-headed ants. They are harmless but can spread a lot of dirt and are a nuisance to see. They do not cause any structural damage to the building but can end up harming houseplants and ornamental plants. If you have potted plants, you might already have these ants present in that soil.


how to get rid of big headed ants

How to get rid of big-headed ants. By Sarefo – Own work, CC BY-SA 3.0, 

Getting rid of all types of ants can be difficult on your own; it is advisable to seek the services of a pest control agency. Since big-headed ants live in the soil and come out in search of food, it can be difficult to eradicate them right from the source. There are a few preventive measures that you can take to make sure these ants don’t enter your home–

  • Keep timbers, logs, and other old wooden items away from the house
  • Make sure your sprinkler system does not spray directly onto the foundation
  • Fix any cracks in the walls, windows, and doors
  • Make sure that the plants and trees around the house are not touching the building – keep them trimmed
  • Treat your garden plants for aphids

Big-Headed Ants Facts

  • Big-headed ant has been declared as one of the hundred world’s worst invaders
  • It is considered a danger to native ants in Australia
  • The genus Pheidole evolved first in Americas
  • Big-headed ants are dimorphic – they have two castes of workers, major workers, and soldiers
  • They also have several queens in their colonies

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