How Fire Ants Stay Afloat: Massive Insect Rafts Save Them from Drowning (VIDEO)

When an area floods, fire ants will work together to create a massive, waterproof raft out of their bodies to stay alive. Now, scientists have taken a closer look at this raft-building behavior, revealing how these industrious insects manage to stay afloat.

Fire ants grasp onto one another with their mandibles and legs at a force of 400 times their body weight in order to create these rafts. Yet scientists wanted to see the strongest parts of the structure and how exactly they connect. That's why the scientists froze ant rafts and then scanned them with a miniature CT scan machine.

"Now we can see how every brick is connected," said David Hu, one of the researchers, in a news release. "It's kind of like looking inside a warehouse and seeing the scaffolding and I-beams."

The researchers found that, on average, each ant in a raft connects to 4.8 neighbors. Although ants have just six legs, they also use their claws, adhesive pads and mandibles to average nearly 14 connections each. In addition, large ants can have up to 21 connections. In out of the 440 ants scanned, 99 percent of them had all of their legs attached to their neighbors-enough to keep the rafts intact even with rough currents. In addition, the ants actually had their legs extended to increase the distance between their neighbors.

"Increasing the distance keeps the raft porous and buoyant, allowing the structure to stay afloat and bound back to the surface when strong river currents submerge it," said Nathan Mlot, one of the researchers, in a news release.

In addition, smaller ants fill the spaces around larger ants in order to keep water from seeping in and guard against weak points. Yet while scientists now know the structure of the raft, they're still unsure exactly how the ants determine to make this structure in the first place.

"Fire ants are special engineers," said Hu in a news release. "They are the bricklayers and the bricks. Somehow they build and repair their structures without a leader or knowing what is happening. They just react and interact."

The findings are published in the Journal of Experimental Biology.

Want to see the ant raft for yourself? Check out the video below, courtesy of YouTube.