Hepper is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

How Do Mantis Shrimp Break Glass? Vet-Approved Facts & Info

Lindsey Stanton Profile Picture

By Lindsey Stanton

Peacock Mantis Shrimp investigating its tank

Vet approved

Dr. Luqman Javed Photo

Reviewed & Fact-Checked By

Dr. Luqman Javed

DVM (Veterinarian)

The information is current and up-to-date in accordance with the latest veterinarian research.

Learn more »

The mantis shrimp, also sometimes known as the Harlequin mantis shrimp, or by its scientific name, Odontodactylus scyllarus, is quite the force of nature. This is one of the larger species of shrimp in the world and can grow up to 7 inches in length. They are fairly big, and they actually look like a mix between a praying mantis and a shrimp, mainly because of their elongated bodies and appendages that look like mantis arms.

The appendages on a mantis shrimp aren’t used for cutting and crushing like a praying mantis. Instead, these appendages, called dactyl clubs, are used for smashing and battering. They use these club-like appendages to batter shellfish until their shells are broken, which is in order to feed on the soft insides. A mantis shrimp’s dactyl clubs can accelerate at a speed of 50 miles per hour (80 km/h) and hit with 160 pounds of force, which is indeed quite impressive and even makes them capable of breaking glass in some circumstances. Other smaller sea creatures usually try to steer clear of these shrimp for that very reason.

How Mantis Shrimp Have The Ability To Break Through Glass

Mantis shrimp have actually been known to attack fingers, often breaking them when they score a solid strike. That is not all though, because they are also known for smashing straight through aquarium glass. This is not something that many people expect until they walk in just in time to see the aquarium explode, sending all of the water and the inhabitants flying out onto the ground. This is very impressive indeed, but how exactly can a 7-inch-long creature smash through aquarium glass?

mantis shrimp in water
Image Credit: Kevin Mc Loughlin, Pixabay

The Dactyl Clubs

The most obvious reason why mantis shrimps have the ability to smash through aquarium glass is because of their dactyl clubs, which they usually use to unceremoniously beat unsuspecting critters over the noggin with. A big reason is because these clubs move at a very high speed, upwards of 50 miles per hour, and hit with a walloping 160 pounds of force. That alone sounds like more than enough to break aquarium glass, but the real secret is in the composition of these dactyl clubs.

The Kevlar-Like Build

The secret behind this awesome power of the mantis shrimp’s smashing abilities lies not only in the speed at which it can strike at, but also in the composition of the clubs. Scientists have noted that were it not for the unique composition of the dactyl clubs, they would almost certainly fracture and break on impact.

The outer layer of the dactyl club is made out of a material called hydroxyapatite, which is a rock-hard crystalline calcium-phosphate ceramic material. Scientists have performed many tests on this material as well as the clubs themselves, and have found that it is stronger than any synthetic material that humans can make. Under this outer layer lay several layers of polysaccharide chitosan, which is a highly elastic and flexible material.

This helps to absorb the impact which would otherwise be taken by the outer layer, which would most likely break without the elastic innards. Each of these inner layers is parallel to the other and is layered in an offset pattern to be at a slightly different angle than the preceding layer. This helps to reduce the occurrence of fractures to the clubs, it reduces the severity of fractures, and it also helps to transfer impact energy to the victim of the strikes rather than to the clubs.

The outer layer of the clubs are also covered in chitosan fibers, which help to hold them together even more while they are bashing away at a critter, your fingers, or aquarium glass. The outer layers of the mantis shrimp’s clubs are so strong that scientists have recently begun performing studies to see how this stuff could replace kevlar and become the new bulletproof body armor.

Why Is My Mantis Shrimp Breaking My Aquarium Glass?

Ok, this is somewhat of a guessing game, even for the most experienced scientists and marine biologists. After all, we as humans do not have the ability to ask a mantis shrimp why it does what it does. For one, they obviously attack human fingers because they see the fingers as either a threat to them or as a potential meal. Either way, it hurts like heck. However, why they smash through aquarium glass is still mostly a mystery.

Some people say it is because they see their reflection in the glass, and thus become territorial and try to kill the “other” mantis shrimp. They may also see some kind of threat on the outside of the glass, or see something that resembles a meal to them. Some people say that the mantis shrimp needs much more space than most people give them, thus they smash through the glass simply to get out of the tank.

Some scientists have even theorized that mantis shrimp smash aquarium glass because they are testing their own capabilities while at the same time strengthening their clubs to be harder than ever. One thing is for sure, and that is that these creatures can be extremely aggressive.




Mantis shrimp are definitely a big force to be reckoned with. They love to kill and eat crabs, clams, and other crustaceans, and they certainly will not hesitate to attack your fingers and aquarium glass too. Just be careful if you plan to have one of these in your home. Most people would recommend an acrylic aquarium as opposed to a glass one, as they tend to stand up to impact much better.

Featured Image Credit: Maxfield Weakley, Shutterstock

Related Articles

Further Reading

Vet Articles

Latest Vet Answers

The latest veterinarians' answers to questions from our database