Fire ants survive floods by becoming a raft… that stings

Fire ants bite. Fire ants sting. Fire ants eat ticks. And when there are floods, fire ants build cooperative floating rafts with their hydrophobic bodies. Then they use trapped air bubbles to breathe while they’re submerged.

These capabilities developed because invasive fire ants “evolved along the river’s edge” in South America. Something called the Cheerios effect helps push them together, too.

This episode of KQED’s Deep Look demonstrates how they bite, sting, and survive, including how red imported fire ants (Solenopsis invicta) lock their legs together like scaffolding and use their young to bolster the raft… which isn’t as bad as it sounds.

“As flood water trickles into the tunnels below their mound, fire ants start a rescue mission. They evacuate the colony’s babies – these larvae and pupae – to the surface.

“But researchers at Louisiana State University found that instead of putting the babies on the top of the raft, where it’s dry, they put them on the bottom…”

“See the halo of hairs on these larvae? If you look at the raft from below you’ll see how those hairs trap air bubbles and hold the larvae together in clusters, you know, like giant floaties.

“Those same bubbles help everyone breathe through tiny holes on the sides of their bodies.”

Follow Deep Look on YouTube, Instagram, TikTok, and at KQED.org.

Watch these related ant and physics videos next:
• The incredible physics of ants and ant rafts
• Sting, prey, raft: The successful behaviors of red imported fire ants
• What makes fire ants “pave roads” with particles?
• Nature’s Scuba Divers – How Beetles Breathe Underwater
• Seven surface tension experiments