Honey bees have two sets of mouth parts. The mandibles or “jaws” are used for chewing. The proboscis is a straw-like tongue used for sucking liquids and also for tasting.
Although it may look smooth and uniform, the proboscis is actually quite complex, composed of several different parts. You can think of it as a tube within a tube. The outer tube is useful for sucking in large quantities of liquid such as water or honey. For example, honey bees may vacuum up large amounts of honey when they are robbing another hive, when they are preparing to swarm, or when they are exposed to smoke.
The smaller tube inside the larger one is used for collecting tiny amounts of liquid such as that found inside flowers. This tube is equipped with a hairy spoon-like tip that helps to mop up the small drops of nectar. The tip also has taste receptors.
The proboscis is also used for food exchange between honey bees, a process called trophallaxis. Food is transferred from bee to bee during the honey-making process, but trophallaxis is also a method of information exchange.
The extended proboscis is about 6.5 mm (1/4-inch) long, a length needed to reach deep into many different flowers. When not in use the proboscis is folded up and stored in a groove-like structure in the bee’s head.