Apple #312: Speed of Ants

I had to drop off my car at the shop today, so since it was such a nice day, I walked home. I saw many interesting things on my walk -- lots of pretty trees in bloom, Canadian geese walking around like portly matrons in crepe gowns, and a beaver working hard to get itself back into the bushes and hide from me while I passed. But the thing I saw that has piqued my interest the most: an ant.

I happened to look down at one point and I saw a fairly large ant, maybe a carpenter ant, and this thing was zooming. I mean, if this ant had been human-sized, it would have been like a speed boat whipping past (except changing directions a couple of times in apparent confusion). We're talking near-warp speed. I even said, out loud, "Whoa!"

So what I want to know is, how fast do ants go?

• A large ant's typical speed is 300 meters per hour. But how fast (or slow) is that?
  

• One scientist who was asked to describe how fast ants move relative to humans said that the question is quite complex because, first of all, ants would be crushed under the weight of their own exoskeletons if they were human-sized, and humans would also be in mortal peril if they were ant-sized.

• But supposing such things were possible and you could shrink a human down to ant size, the human would walk at about 18 meters per hour. That's about 1/16 the rate that the ant travels.
  

• Put another way, it would take the ant-sized human 100 hours to walk 1 mile. The ant would cover that same mile in about 5 and a half hours.

• Now let's put the ant's speed in human-sized terms.

• Assume the ant is 1/4 inch long. That's about the size of a worker carpenter ant, which is considered a "large ant."
  

Carpenter ant
(Photo by L. Jesse from Iowa State University)

• If this carpenter ant travels 300 meters per hour, that converts to about 196 inches per minute. Which amounts to 787 times the ant's body length in one minute.

• Assume a human is 6 feet tall. At the same rate as the ant, the human would cover 787 times its size, or 4,723 feet per minute.

• Put that in a unit most people (including me) could recognize, and that's 53.6 miles per hour.

• This is all just a method to arrive at a fairly good guess. But that ant looked to me like it was going even faster than 53.6 miles per hour. I might clock it at 60, at least.
  

MORE SPEEDY ANT FACTS

• A couple of years ago, scientists discovered that the animal with the fastest jaw-bite is the trap jaw ant, which lives in Costa Rica. This ant can snap its jaw at 145 miles per hour.

• You might not think that is such a big deal, except this is faster than cheetahs, sharks, crocodiles, all those big scary animals that can clamp you in a death grip faster than you can say, "That's my leg."

• The way it works is they keep their jaws back in a cocked position and then they trigger a little latch which releases the muscles, and zappo!

The Trap Jaw Ant. Its mandibles (jaws) are thick black things projecting straight out from in front of its face. The long skinny things extending toward the camera are its antennae.
(photo from the LiveScience Image Gallery)

• These trap jaw ants don't just use this super-fast jaw speed to bite their prey, they also use it as an escape mechanism. Turning its head down, the ant snap its jaws into the ground or off the body of its would-be-prey, which launches the ant up into the air anywhere from 3 inches to 16 inches away.

• Put in a distance relative to our size, if we could do something similar, we would be propelling ourselves over 44 foot-tall buildings.

• Put another way, these ants are generating, with their jaws, forces 100,000 times that of gravity. As one scientist said, "Not even the space shuttle gets that many Gs [units of gravitational force]."

• Entomologist Ben Fisher is the one who figured this out, and he did it using super high-speed cameras. And really, check out these videos:
  

• Video of a trap jaw ant doing the vertical escape thing. The video is playing at 100 times slower than real time.

• Video of a trap jaw ant bouncing itself away. Again, at 100 times slower than real time.

MORE ANT FACTS

• Entomologists classify ants as a group of wasps.
  

• Depending on the species, an ant can lift 20 to 50 times its own body weight.

• Ants never sleep.

• On the other hand, if they're not the queen, most ants only live about a 1-1/2 to 2 months.

If you liked this entry, you might also be interested in reading about Ant Muscles.

Sources
MadSci Network, What is an ant's speed in proportion to a human?
California Academy of Sciences, "Trap-Jaw Ants Set Speed Record," August 15, 2006
Jenny Cutraro, "Ant With Lightning Jaws Makes World's Fastest Strike," National Geographic News, August 21, 2006
John and Sarah's Free Materials for Teachers, Interesting Facts about Ants
Travel Africa, African Army Ants
Brandon B., Makalapa Elementary School, The World of Ants
Online Conversion, length and distance