How Do Bugs Breathe?

That is a bigger question than you would think. When you hear bug, most people only think of insects. But not all bugs are insects. Rollie pollies are actually  crustaceans. Spiders and ticks are arachnids. Then there are centipedes, millipedes and all kinds of worms. Yet they all get put into the group called bugs.

Most bugs do not have lungs. The have tiny holes in their abdomens called spiracles. These can be opened and closed as needed. These lead to little channels called tracheae that carry oxygen to the cells. Some bugs just let air come in by itself; Others, like grasshoppers, can expand and contract their abdomens to obtain more oxygen. Bugs don’t have blood. They have a clear, yellowing fluid called hemolymph that carries nutrients and oxygen inside their bodies.

Some creatures, like spiders, have what are called book lungs. They are structures that have thin, stacked, membranes that look something like pages in a book. They can fan these and let oxygen in. Others like rollie pollies have gills! They need to always remain moist. That’s why the need to live in moist areas like under rotten logs.

Water insects like the larva of mosquitoes and midges have an air snorkel that they can use at the water’s surface to breathe while they look for prey under the water. Others have visible gills. Some insect even carry a bubble of air around their abdomens while they are diving under water.

There are even bugs, like worms, that can breathe through their skin. They also need to always stay moist so that oxygen can absorb into their bodies.

Because most bugs have to get their oxygen these ways, it puts a limit on how big they can grow. It is thought that back in history (probably before the Great Flood) oxygen levels may have been greater. This could help them to grow much bigger, something we can see in some fossils.

What amazing creatures we have around us! I hope you liked hearing about them.

Until next time,

Love Papaw.