External structure of ants
As with all insects ants' body is made up of 3 parts: head, thorax and abdomen. What is specific about ants is the presence of a petiole (a segment which connects the thorax with the abdomen). It makes it possible for the ant to reach the tip of its abdomen with its mandibles. This can be useful when laying eggs as well as when fighting - the ant grasps its enemy with its mandible anf stings it (for some species) or sprays in the wound, caused by the mandibles, the formic acid (an acid the ant produces by a gland - HCOOH).
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Head - This is where the sense organs and the mouth of ants are:
- Antennae - The main sense organ of ants. They are made up of two main segments, connected through flexible connections, so that they can stretch them forward (when investigating an object), as well as fold them to their body (when fighting). Thanks to their antennae ants receive information about the form and the shape of an object, as well as sense sounds and chemicals.
- Eyes - Ants, like most insects, have two types of eyes: the compound eyes and the ocelli. The compound eyes are relatively badly developed due to the mainly underground way of life. Ants use their ocelli to sense the presence of light.
- Mouth - The mouth of ants (like of most insects) is made up of several parts. The largest one is the mandibles. They can be opened widely or closed firmly together. Near the mouth ants have one more pair of small tentacles, which are most likely used to taste food. Ants have a flexible tongue too. On it the food goes to the digestive system and gets filtered from undigestive waste by a special organ.
- Antennae - The main sense organ of ants. They are made up of two main segments, connected through flexible connections, so that they can stretch them forward (when investigating an object), as well as fold them to their body (when fighting). Thanks to their antennae ants receive information about the form and the shape of an object, as well as sense sounds and chemicals.
- Thorax - It carries 3 pairs of legs, and in males and females 2 pairs of wings. Legs are very flexible, completely adjusted to moving on rough terrain and on unfavourable slope. The petiole carries two oil glands, which ants most likely use to oil their body. There are also 3 holes, that ants breathe through.
- Abdomen - It carries important organs. It can get larger or smaller through flexible connections between the segments depending on the need. On the tip of the abdomen is the anus and an opening for laying eggs (in queens), as well as a sting (in some species).
- Cover - The cover of ants (exoskeleton) as in most insects is hard, out of sclerotin and is used for mechanical protection, as well as for keeping the body from water loss. There are numerous tiny organs on it, from which ants take information about the position of their body. The flexibility of the body is achieved by flexible connections between the segments it is made of. Differently from most insects ants are rarely more than two-colored.