Fire ants - sting, prey, raft

If you live in the southeastern United States like I do there's a good chance you've been stung by a fire ant. Given how common fire ant stings are, I was surprised at how hard it was to find detailed videos of stinging behaviors online. I study ants and I use videos a lot to do it, so I decided to see if I could capture the details of fire ant stings and other behaviors on film. This fire ant worker is on my finger. Her sting starts with the bite. The worker sinks her mandibles into my skin, then she starts to probe around for a place to insert her stinger. Okay wait, hold on, this is my favorite part of the video. I want to make sure you see it. Look right here. Between the mandibles. You can see her extend her mouthparts, her tongue basically, and actually lick my finger. The stinger is at the tip of the abdomen. If we zoom into just the stinger in this shot, you can see a droplet of venom form when the sting lancet is actually pushed out of the sting shaft. An average fire ant worker has a reservoir containing around 30 nano litres of venom connected to their sting. Though dosage can vary between ants, a typical sting injects around 0.7 nanoliters of venom. Fire ant stingers are not as heavily barbed as honeybees. So after venom injection the ant can walk away pulling out the stinger and continue on unharmed and able to sting again. But stinging isn't the only behavior that makes fire ants and successful species. They're also really good at collective group level behaviors. Take prey capture for instance. This beetle is 25 times heavier than a single fire ant. Multiple workers have to be recruited to sting the beetle before it succumbs in the ants. Once it's immobilized, they cooperate in dragging the beetle back into the colony. If the beetle is unmovable, the ants have to work together to chop up the larvae into small bits and transport those back to the nest. At a whole colony level, rafting is a collective behavior that fire ants are famous for. In their native range in South America, flooding that's pretty common. In response to a flood an entire county will emerge from the ground carrying their eggs larvae and pupae. As the water level rises, the ants cling to each other forming a living raft that their nestmates gather on. They can float like this as a colony for days until floodwaters recede or they reach higher ground. From individual stings to whole colony rafts, behaviors of the red imported fire ant Solenopsis Invicta have helped them become one of the most widespread invasive ant species.

Channel: Ant Lab

Views: 55,509

Rating: 4.9492245 out of 5

Keywords: fire ant, fire ants, ant sting, ant venom, ant stinger, ant raft, ant float, solenopsis, solenopsis invicta, RIFA, red imported, invasive ant, ant invasion, red ant, ant pest, ant behavior, ant ecology, ant predation, ant predator, beetle larva, beetle larvae, myrmecology, venom gland, poison gland, ant poison, fireant, fire sting, stinger

Id: F60agY1IpmU

Length: 3min 2sec (182 seconds)

Published: Thu Aug 02 2018