Stick insects are the favorite food of many animals. All sorts of birds, lizards and mammals like to eat a tasty stick insect. How does one prevent to be eaten?
There are a few different methods for that:
To prevent being noticed by predators, a stick insect can look like a stick or leaf. Most stick insects use this method to prevent being eaten.
Spikes and thorns
Some stick insect species have spikes and thorns all over their body. This makes them difficult to be eaten by small predators. Some stick insect species can even pinch with spikes located on their hind legs, sometimes allowing them to fight off a predator.
Scary sounds and colors
Some species of stick insect are able to produce sounds with their wings or legs. This can deter predators, especially predators that are young or that are unsure if a stick insect is proper food for them. Most stick insects with bright colors are also poisonous.
Poisonous stick insects are toxic when eaten. There are no venomous stick insects (they have no toxic bites or stings). Unually the toxins also taste bad. Poisonous stick insects often have bright colors, so the predator is warned before it takes its first bite. The toxin could be deadly to the predator, but usually it just makes the attacker feel sick or irritated. Some stick insects, like Peruphasma, can spray an irritating substance from glands on their back onto their attacker. This can irritate skin and eyes, allowing the stick insect to deter predators long enough to escape.
The following video shows a stick insect with bright colors. It also produces a warning sound with its wings in the video. The species name is Achrioptera fallax and it is a poisonous species.