A proboscis is a long, tube-like mouthpart that some animals use for feeding or drinking. Think of an elephant's trunk: that's actually a proboscis, though we usually just call it a trunk. Butterflies have a proboscis too, a thin coiled tube they uncurl to sip nectar from flowers, like drinking through a bendy straw.

A mosquito uses its needle-thin proboscis to pierce your skin and drink blood (which is why mosquito bites itch). Moths and many other insects have proboscises adapted for reaching deep into flowers. Some flies have a sponge-like proboscis for soaking up liquids.

The proboscis is well suited to each animal's needs. A butterfly's proboscis can reach nectar that other insects can't access, while an elephant's proboscis can grab food, spray water, or even greet other elephants. Scientists sometimes use proboscis playfully to mean a person's nose, especially a large or prominent one, though this usage is informal and can be a bit cheeky.