Ants have setae, which are hair or bristles on their exoskeletons. They use these setae as sensory receptors and for a variety of purposes including communication, locomotion, and thermoregulation.
In this article, we’ll we further discuss what setae are and what they’re used for.
What Is Setae?
Again, setae are a number of hair or bristles found on the ant integument. These setae are hollow structures developed as extensions of the exocuticle and are produced by two specialized epidermal cells, the trichogen and tormogen cells. The former is an enlarged cell that secretes the long tapering hair while the latter forms the socket around its base.
Depending on the species, setae may appear scattered or in patterns on an ant’s body and appendages. As such, they’re important for the identification and classification of species. For example, workers of the Argentine ant Linepithema humile can be separated from similar ants from the genus Forelius through their long clypeal setae that extend past their mandibles when closed.
Why Do Ants Have Hair Or Setae?
Similar to our hair, setae are primarily used for mechanoreception or to detect different types of stimuli. They’re innervated with neurons which receive sensory input and send motor commands that let ants respond accordingly to a specific stimulus.
Aside from mechanoreception, ants also use setae for a number of different purposes including the following:
Communication. Ants rely on the fine hairs and other receptors in their antennae to sense and communicate. Without these fine hairs, ants will have difficulty finding food, and picking up scents and pheromones. In fact, research has found that damage to fine hairs on the tropical weaver ant antennae compromise the ants’ ability to distinguish friend from foe. This highlights the importance of setae in the ants’ olfactory system, that of which serve as their primary means of communication.
Grooming. To keep their antennae in tip-top form, ants use the setae of a claw-like structure in their front legs to comb and remove dirt from their antennae. This structure consists of both coarse and fine setae to ensure that no sort of debris or pollen remains.
Locomotion. Ants also use the hairs on their feet to move from one place to another. These dense hairs generate friction and work alongside the adhesive pads on their feet to help ants stick to and climb walls or other surfaces.
Thermoregulation. Lasty, ants make use of setae to control body temperature. Research has found that Saharan desert ants use setae to stay cool and survive the scorching desert heat. These ants have uniquely shaped triangular hairs on the top and sides of their bodies which help keep them cool by reflecting light, and therefore heat, away. It’s been also revealed that these hairs enhance the Saharan desert ants’ ability to offload excess heat and provide them with a passive cooling ability when exposed to the clear sky.
Do Ants Have Teeth?
Ants have mandibular teeth attached to their mandibles. The number of these teeth vary depending on species and their mandibular structure, but ants generally have apical and pre-apical teeth.
Do Ants Have Eyes?
Most ants have a pair of compound eyes while some species may also have one to three simple eyes called ocelli found on the dorsal surface of the head. There are also some ant species, particularly the subterranean ones, which have no eyes at all.
Do Ants Have Wings?
Some ants have wings and are capable of flying. These winged ants are typically reproductives which mature colonies produce at certain times of the year for the purpose of breeding and establishing new colonies.
Summary: Do Ants Have Hair?
Ants have hair called setae scattered around their bodies and appendages. These setae are extensions of the ant exocuticle and are innervated with neurons which allow them to pick-up a wide variety of inputs and stimuli. As such, setae is used for mechanoreception, communication, grooming, locomotion, and thermoregulation.