Insect protect itself by bleeding and vomiting
The armoured ground cricket (Acanthoplus discoidalis) has an, intentionally, disgusting mode of self-defence. When attacked it vomit all over itself and squirt green, acrid blood from hidden orifices. From BBC:
“What impressed me is that they control the release depending on how they are grabbed,” says [entomologist Bill] Bateman, describing the actions of the armoured ground cricket.
“If it’s from above the blood wells out and coats your hand. If grabbed by forceps from the side, by a leg, they lean towards it and crouch down, then there is a slight cracking sound and the blood jets right along the line of attack.”
“Any predator would get a faceful, and our experiments indicated that lizards do not like it all.”
No, I bet they don’t.