Ironclad Beetles – Everything You NEED to Know

The ironclad beetle is well known for being extraordinarily tough and resilient, and it is often referred to as indestructible.

These beetles can live for up to about eight years in some circumstances, which is far longer than other beetles. They cannot fly, and they can grow to just over an inch long.

Ironclad beetles are almost impossible to kill with pressure, and they can survive a force of up to 39,000 times their body weight.

Some of these beetles can even handle being run over by a car, and you will probably find that you can’t crush one even if you try. Most predators cannot tackle these insects because they are so tough.

We are going to look at:

  • Why are ironclad beetles so resilient?
  • What do these beetles eat?
  • How long do they live?
  • How do predators handle them?
  • What do they look like?

What Makes The Ironclad Beetle So Tough?

It’s unusual for beetles to be able to withstand anything like the amount of force that this beetle can withstand, hence its descriptive name.

Although most beetles are tough and have rigid exoskeletons that can withstand some pressure, very few can withstand being stepped on, let alone run over by a vehicle.

So, what makes the ironclad beetle so special? It has taken a long time to find out, and science now thinks there are two key factors behind this bug’s toughness.

The first is that the exoskeleton is made up of impact-absorbing, tightly interlocked structures. The exoskeleton is formed in two halves, and the outer edge of the top half and bottom half are latched together with ridges.

The shape of the ridges varies along the beetle’s body, and near the front of the beetle, they are extremely tough and unyielding.

This is where the beetle’s vital organs are, and this is the part of its body that most needs protecting. These ridges will not bend when pressure is put on them.

Sqwertz, CC BY-SA 4.0, via Wikimedia Commons

By contrast, the ridges at the lower end of the body are more flexible. The two halves of the exoskeleton have some movement, and this helps the beetle to absorb pressure without it mattering; there are no vital organs to get squashed here.

That’s the first feature that prevents the ironclad beetle from being squashed easily. What about the second?

The beetle has a rigid suture running along the whole length of its back and connecting the right and left sides of its body together.

This suture has protrusions, rather like the shaped edges of a jigsaw puzzle, that slot into either side, joining them together.

Katja Schulz from Washington, D. C., USA, CC BY 2.0, via Wikimedia Commons

These protrusions have layers of tissue that are extremely damage-resistant, made up of protein. When these are put under pressure, small cracks form in them, which allows the beetle to absorb the impact because a part of its body is giving way.

The beetle is then able to heal these cracks after the pressure has been removed. The beetle can continue with life as normal, and will not be worse off for being trodden on or crushed.

It is extraordinary what these beetles can withstand. Humans are studying how their bodies work and using these designs for our own engineering projects.

How Tough Are They Really?

So, what does all that clever engineering mean?

For starters, if you stand on an ironclad beetle, you have almost no chance of killing it. It will simply crawl off once the pressure is removed. You could also run these beetle over with a car and it would be likely to survive.

Some people say that they are also extremely resistant to other potentially deadly situations. They do not drown easily, for example.

If you rescue one from a bucket of water, you will likely find that even if it seems dead, it soon revives and crawls off.

The ironclad beetle has definitely earned its name, because it is extremely tough. It is possible that it evolved its resilience partly due to its lack of flight; the beetle has lost its wings and cannot take to the air.

That may have meant it had to find other solutions to avoid being eaten by predators. Alternatively, the beetle may have lost its wings after developing its strong exoskeleton, as they would have become fairly superfluous.

An ironclad beetle does not make an easy meal for most predators. They can be swallowed whole by threats that are large enough, but birds will struggle to break them up into manageable pieces, and small predators cannot attack them because they can’t chew them.

Lizards, for example, will eat other kinds of beetles, but not ironclads. They simply cannot tackle them.

What Do Ironclad Beetles Eat?

These beetles eat mostly rotten wood and dead plant matter. The larvae and pupae are usually found on dead wood, especially on pecan trees. Adult ironclads are often found on oak trees, feeding on the lichens that grow there.

It is not thought that these beetles damage living plants, so you don’t need to worry if you find them on your garden plants. They are probably just moving through and will not hurt them.

How Long Do Ironclad Beetles Live?

These beetles can live for an amazing eight years, which is a very long time for a beetle. Clearly, all that armoring pays off, because most beetles only live for about three years at the most, and much of that time is spent as larvae.

What Do Ironclad Beetles Look Like?

There are 19 species of this beetle, so there are quite a few variations in how they look. However, many ironclad beetles are black and white, making them extremely distinctive and quite eye-catching.

This makes them much more obvious to predators, but because the beetles are so tough, most predators can’t take them on.

Greg5030, CC BY 3.0, via Wikimedia Commons

They can deal with being pecked by birds, so even if a bird can spot this insect, it is unlikely to be able to eat it.

Some people have suggested that the ironclad’s decoration is supposed to mimic bird droppings, making the insects harder to see.

It’s also possible that it is an attempt at camouflaging themselves in the tree lichens that they feed on, or matching decaying wood.

It should be noted that some of these beetles lack the white coloration and instead are entirely black. These ones are much harder to spot on the whole, but it isn’t clear why they lack the white that others in the family have.

Where Are These Beetles Found?

Because there are quite a few kinds of ironclad beetles, it may not surprise you that they can be found in lots of different places. Ten of the species live in North America, and they are spread from Texas to Venezuela. They are also found in Colorado, Nevada, Utah, and other Western states like California.

The Texas ironclad is one of the most famous of all the ironclad species, so you won’t be surprised to hear that these beetles are common there.

Insects Unlocked, CC0, via Wikimedia Commons


Ironclad beetles are truly extraordinary and have fascinated people for years. They are a real example of just how amazing nature can be, and the cleverness with which it develops in the fight to survive.

Alright, that’s it for this article, here are a few hand-selected articles that you might also find interesting reads:

The Color of Beetles – Blue, Black, Orange and Many More!

Why Am I Finding Beetles In My House?

Which Bugs Live the Longest?

Steve Foster

Mad about bugs and wanting to publish as many articles as I can to help educate people about these amazing beautiful creatures! For more info check out my about page

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