Written by Nancy Miorelli

Simple answer is yes and yes!
There’s a couple reasons why insects spit or vomit.

I’m spitting into this beetle right now, you know, cuz I gotta eat too.
PC: Gbohne (CC by SA 2.0)

1. The first is to protect itself.
2. To help digest food.

But lets look at some specific examples.

1) Protection

Tenacious Termites

Termites may not seem very cool, as they’re blind and just putter around inside dead logs all day. Ants are their enemies. Ants are fast and have jaws of death – two things that the slow squishy termites can’t handle.

However, the soldiers pack a punch. Or a spit, as the case may be.
Termites of the genus Nasutitermes jet-spray a sticky string of irritants and repellents from their cone heads which they aim at ants. The string of goo not only traps the ants but also calls other termites for backup. If you look closely you can see the termites in the video below spitting at this person’s finger.

Gnarly Grasshoppers

Grasshoppers, katydids, crickets, and lubbers in general vomit pretty much whenever they’re scared. They’ll puke on you if you’re just picking them up and trust me – I’ve been puked on by many a grasshopper.

Some people call the smelly vomit “Tobacco juice”, but whether you call it that or just “gross” it’s a brown liquid that smells pretty bad. And tastes really bad too. It lets predators know that the grasshopper tastes bad and is probably poisonous too.

Back off, bro. Seriously, I taste bad.
PC: Backyard Arthropod Project

Cozy Caterpillars

While not “spit” exactly, caterpillars spin silk from the spinnerets located near their mouth. The silk protects their squishy and vunerable pupa stage from predators.

Some caterpillars spin elaborate homes out of their silk to protect themselves, like these tent caterpillars.

Nice and roomy inside.
PC: JackFrost2121 (CC by SA 3.0)

Others caterpillars, like the silkworm, we specifically raise to get their silk. And then we make what would have been a protective covering into a dress. So I guess that backfired a little.

Raw silk from the silkworm.
It’s not actually a “worm” but a caterpillar.
PC: Elkagye (CC by SA 3.0)

Sneaky Spittlebugs

Spittlebugs are called this because of the white foamy “spittle” they produce. However, this name is really misleading because it’s not actually spit! This foamy froth is actually produced from their abdomen!

Baby spittlebugs that aren’t old enough to fly make the froth around themselves to hide from predators. If things try and eat the baby spittle bugs anyway, they’d soon find out that the “spit” also tastes really bad. The froth also helps protect the spittle bugs from temperatures that are too hot or too cold.

Spittlebug Spit – but you know, it isn’t actually spit.
PC: Brad Smith (CC by NC 2.0)

2) To Eat

Some insects can’t digest things on their own very well. So they have a couple strategies to get around this.

Rude Reduvids

The family Reduviidae – 0r Assassin Bugs eat other bugs. They stab their tube-like mouth into their fellow insect and suck it dry. They’re not the only bugs that go about this method. Some Stink Bugs and others in the group of bugs called “Hemiptera” lead this lifestyle too.

Modeled Extra Oral Digestion
PC: Nancy Miorelli

I talked about this before in an earlier post, but these insects have components of their spit that help them digest things. We do too! Our spit helps us digest carbohydrates. That’s why if you suck on dry pasta for long enough, it gets mushy and kind of sweet.

Anyway, these bugs spit into their helpless victim. The spit eats the prey away from the inside out. Then the Assassin Bug slurps it all up like a slushie.

Mmmm beetle flavored slushie. My favorite.
PC: Andy McLemore (CC by SA 2.0)

Heaving House Flies

Houseflies also have to start digesting their food outside their body. However, these guys just slurp a whole bunch up, then throw it back up. They then re-eat their half digested puke. Yum. We can use this behavior to help us solve crimes, but you can read all about that here =)

The puke bubble. It’s practically seconds.
PC: Alvesgaspar (CC BY-SA 3.0)

Bee Besties

A lot of  bugs which live in colonies vomit in order to feed each other. Liquid foods are really hard to carry, so a lot of bugs simply carry liquids in a special part of their tummy called a ‘crop’. When bees get back to the colony, they ‘deposit’ the nectar they ate when they left into the honeycomb. They then let it dry into a syrup.

This is how we get honey.

Honeybee making honey. Don’t let the description of the process gross you out, because honey is still totally delicious. Picture credit: Mathew T Rader, via Flikr License info: CC By NC-SA 2.0

 The Bottom Line

Bugs can barf if they get sick, just like when people get sick. There’s a lot of different things you can do with barf, though. Barfing on food is a good way to break it down, and a bug’s tummy can work like a lunchbox if needed.

We don’t recommend using barf like a bug, though.

If you want to know if insects can choke – check out this follow up post!

Post was edited by Joe Ballenger