How do Insect drink water?

Answer 1

As a simple answer, yes, insects do drink in

the same way as other animals, but there is a little more to it than that.

Firstly, it depends on the rest of the insect's diet as you rightly point

out. Many herbivorous insects get the majority, if not all, of their fluid

from the food they eat because vegetation has such a high water content. I

have some tropical stick insects and they certainly get all their water

from the leaves they eat, although they are kept in a damp environment. It

is also worth noting that their mouthparts are not particularly effective

for drawing water anyway.

It is not uncommon for insects to drink from the morning dew, from

raindrops, or from the surfaces or edges of ponds. Leave a damp tissue out

on a hot day (make it bright yellow to attract the most insects) and watch

them come in to drink. If you watch with a magnifying glass you will see

that they have many different ways of doing it; flies suck it up, and

wasps use a tiny structure that looks much like a tongue. While mentioning

wasps, it is worth thinking about nest building which is done by biting

tiny pieces of wood and bark and chewing them into a paste from which the

nest is made. This requires water and so the wasp needs to take on

moisture for this purpose too. I have two giant millipedes (not insects,

but arthropods all the same) that augment their cucumber and tomato diet

with a considerable amount of water that they draw from the damp soil

around them.

As a general rule, the ability to go without water is confined to small

animals, and the larger an animal is, the more it depends on water. This

could suggest why the bigger insects are usually to be found in warm wet

places such as the rainforests.

Finally, to answer your question about carnivorous insects, lets look at

robber flies and mantids. Both are ambush style predators, one of which is

common worldwide, whereas the other is usually only found in warmer

climates. Both have a diet that is made up of prey, but the robber fly

will take juice from fruit and the mantis will sip water from leaves when

it gets thirsty.