Narrator: At first
glance, a fire ant hill - or mound, as it's properly
called - looks impossibly small. And yet a colony of up to
250,000 ants call it home. But here's the secret: that mound is just the tip of an enormous iceberg. So let's take a closer look
at what's inside an anthill. The mound is really the top of an enormous underground
structure: the nest. Which is basically a giant
nursery: a nice, cozy place to raise babies. A lot of babies. Their mother, the queen,
roams around the nest while laying 1,500 eggs a day! Now, all those baby ants need to live in a narrow temperature range to grow. So that nest sports
temperature-controlled rooms. And it does so without
the help of an AC unit. The secret's in the design. The nest is arranged
like an ice cream cone. At the top, you have the mound
- the ice cream, as it were. Because it's above the surface, it warms up from the heat of the sun, so the babies can snuggle
up in toasty chambers networked throughout the mound. But they can't stay there all day, or they'd get too hot. That's where the cone part of
the ice cream cone comes in. The mound is connected to
several vertical shafts that plunge up to two
meters beneath the ground. That's taller than most humans. Throughout the day, adult
ants ferry the babies up and down the shafts, chasing
that perfect temperature for their young charges. The nest also sports
dozens of tapering tunnels that branch off from these main shafts. These connect to small chambers
where the ants rest, eat, and feed the babies until it's time to move the little ones once again. Now, there's one more type
of tunnel inside the nest, but only a few ants ever use it. You see, someone needs to find food for the rest of the colony, but running around outside the
nest is dangerous business. That's where forager tunnels come in. These are a couple of horizontal passages buried just a few
centimeters from the surface. But they run throughout
the entire territory, which can cover up to 185
square meters of land. By scurrying through these passageways, the scouts can stay underground
as long as possible. But unfortunately, the
nest and all its roads can't protect the ants from every threat. It turns out all sorts of critters sneak inside fire ant nests. And while many of them
are actually harmless, others are horrible houseguests. For example, beetles burrow into the nest and devour the eggs and larvae. But invaders aren't the
only threat to the colony. Occasionally, clueless humans or major floods disturb the nest. And when that happens, the fire ants have only one option, leave. Once a year on average,
the colony will move out and build an entirely
new nest from scratch. And best of all, they only
need a few days to do it. That's right. Practically overnight, meters upon meters of tunnels
can pop up in your yard. And all you'll notice is a tiny mound.
