You walk outside one summer evening and notice a bright green insect sitting perfectly still on your deck railing.
At first glance, it looks like a giant grasshopper.
Then you notice something unusual.
Its antennae seem impossibly long, stretching far beyond the length of its body.
If you’ve spotted an insect like that, there’s a good chance you’ve found a katydid.
Katydids are fascinating insects that are often mistaken for grasshoppers because of their similar body shape and powerful jumping legs. Despite their size and appearance, they’re generally harmless to people and spend most of their lives quietly hiding among trees, shrubs, and other vegetation.
The Short Answer
Katydids are green, leaf-like insects best known for their extremely long antennae and loud nighttime calls.
Most species have:
- Bright green bodies.
- Antennae longer than their bodies.
- Large jumping back legs.
- Wings that resemble leaves.
- Excellent camouflage.
Although they can startle people because of their size, katydids are not considered dangerous and rarely cause problems around homes.
How to Identify a Katydid
The easiest way to identify a katydid is by looking at its overall shape.
Unlike many grasshoppers, katydids have an appearance that helps them blend almost perfectly into leaves and tree branches.
Some of the most noticeable features include:
- A bright green body.
- Very long, thread-like antennae.
- Long, powerful hind legs for jumping.
- Wings that look remarkably similar to leaves.
- Large, rounded eyes.
One of the biggest clues is the antennae.
In most katydids, they’re much longer than the body itself and are often the first feature people notice.
The Katydid I Photographed
The katydid in the photos above was resting quietly on a wooden railing during the evening.
It stayed almost completely still, relying on its camouflage instead of trying to escape.
One detail that’s easy to see in these photos is the extremely long antennae, which are much longer than the insect’s body. You can also see the leaf-like wings beginning to develop over the back and the powerful rear legs that allow katydids to make impressive jumps when disturbed.
These features are some of the easiest ways to separate a katydid from a typical grasshopper.
Are Katydids the Same as Grasshoppers?
Not quite.
This is one of the biggest misconceptions about katydids.
Although they’re closely related and both belong to the order Orthoptera, katydids and grasshoppers belong to different families and have several easy-to-spot differences.
Here’s a quick comparison.
| Katydid | Grasshopper |
|---|---|
| Extremely long antennae | Short antennae |
| Usually bright green | Green, brown, or tan |
| Mostly active at night | Mostly active during the day |
| Leaf-like wings that provide camouflage | Wings usually do not resemble leaves |
| Loud nighttime songs | Chirping or buzzing sounds, often during the day |
If you’ve found a green insect with antennae that seem longer than its body, you’re almost certainly looking at a katydid rather than a grasshopper.
Are Katydids Dangerous?
Fortunately, no.
Katydids aren’t considered dangerous to people or pets.
They don’t:
- Spread diseases.
- Damage homes.
- Destroy furniture.
- Infest kitchens.
- Invade pantries.
Most homeowners simply find one resting on a porch, deck, garage wall, or patio during the summer before it eventually moves on.
Because they’re so well camouflaged, you may actually have dozens living around your yard without ever noticing them.
Do Katydids Bite?
Katydids aren’t aggressive and have no interest in biting people.
However, like almost any insect, they can occasionally give a small defensive pinch if they’re grabbed or squeezed.
Even then, it’s uncommon and usually no worse than a minor pinch.
They don’t seek people out and aren’t considered a biting household pest.
Why Are Katydids Green?
Their color is one of their greatest survival tools.
Most katydids spend their lives among:
- Tree leaves.
- Shrubs.
- Tall grasses.
- Garden plants.
- Bushes.
Their green bodies help them disappear into the surrounding vegetation, making them much harder for birds, reptiles, and other predators to spot.
Some species are so convincing that even experienced nature lovers can overlook one sitting in plain sight.
Why Are Katydids So Loud at Night?
If you’ve ever heard loud, repetitive chirping on a warm summer evening, there’s a good chance a katydid was responsible.
Male katydids produce their familiar songs by rubbing one wing against the other, a process known as stridulation.
The calls serve several purposes:
- Attracting females.
- Establishing territory.
- Communicating with other katydids.
Different species produce different songs, which helps them find the correct mates.
For many people, their calls are simply part of the soundtrack of late summer.
What Do Katydids Eat?
Katydids are primarily plant feeders.
Their diet commonly includes:
- Leaves.
- Flowers.
- Grass.
- Shrubs.
- Fruits.
- Seeds.
Some species will also eat:
- Small insects.
- Aphids.
- Caterpillars.
- Insect eggs.
Because of this varied diet, most homeowners never notice them causing significant damage.
A few may nibble on garden plants, but they’re rarely serious pests.
Where Are Katydids Usually Found?
Katydids prefer areas with plenty of vegetation.
They’re commonly found in:
- Backyards.
- Forest edges.
- Meadows.
- Gardens.
- Parks.
- Tall grasses.
- Trees.
- Shrubs.
During the day they often remain perfectly still, blending into leaves so well that they’re almost impossible to spot.
As evening approaches, they become much more active and their distinctive songs begin.
What Should You Do If You Find One?
In most cases, nothing.
Katydids are beneficial parts of the outdoor ecosystem and don’t usually require any control.
If one accidentally wanders indoors, simply capture it in a cup or container and release it outside.
Unlike many household pests, katydids don’t establish indoor infestations and rarely survive long inside a typical home.
My Experience
Katydids are one of those insects that surprise people simply because they don’t see them very often.
The first thing most people notice is their incredible camouflage.
The second is those unbelievably long antennae.
If you spend time outdoors during late summer, you’ll probably hear far more katydids than you’ll ever actually see.
Once you know what to look for, though, they’re fascinating insects that are well worth appreciating rather than fearing.
Frequently Asked Questions
Are katydids harmful?
No. Katydids are harmless to people and are not considered household pests.
Can katydids bite people?
They rarely do. A katydid may give a mild defensive pinch if handled roughly, but they aren’t aggressive and don’t seek out people.
How can you tell a katydid from a grasshopper?
The easiest way is to look at the antennae. Katydids have very long antennae, often longer than their bodies, while grasshoppers have much shorter antennae.
Why are katydids so hard to see?
Their leaf-like bodies provide excellent camouflage, allowing them to blend almost perfectly into trees, shrubs, and other vegetation.
Should I remove katydids from my yard?
Usually not. They’re a natural part of the outdoor ecosystem and seldom cause enough plant damage to justify removing them.
About the Author
Nathan Reynolds is an outdoor naturalist and insect educator who has spent more than 18 years photographing and studying the insects commonly found around homes, gardens, and wooded landscapes. He enjoys helping homeowners identify unfamiliar insects and better understand the important role they play in nature.
