Do fire ants leave anything inside you when they bite you?

If you are wondering whether they leave any part of their body such as their mandibles embedded in your skin, then no. They do inject a poison, however. Unlike many other ants, which bite and then spray acid on the wound, fire ants only bite to get a grip and then sting (from the abdomen) and inject a toxic alkaloid venom called Solenopsin, a compound from the class of piperidines.