Deep in a rain forest, a leafcutter ant finds a tasty patch of leaves. It snips off a bit of a leaf. T en it heads back to the nest it shares with millions of other ants. Soon, other ants start marching to the same patch. T ey snip leaves and carry the leaf bits back to the nest, too. T e ants knew exactly where to go. T ey
smelled the way. With each step, the first ant let out chemicals from a gland in its abdomen. T is body part makes a useful substance. T e ant used it to make a trail of smells. When the ant got back to its nest, the other
ants wriggled their antennae. T at’s the body part they use to smell. T ey quickly sniff ed out the first ant’s message. It said, “Food this way!” Ants can make more than 12 chemical
smells. Each one says something diff erent. For instance, one smell asks for help. Another screams, “Danger!” T at smell message comes in handy when an army ant invades. T is ant is bigger than a leafcutter ant. Worse yet, it eats leafcutter ants. T e army ant smells like a stranger. T at
smell tells a leafcutter something is wrong. So the leafcutter makes the alarm smell. Other leafcutters get the message. T ey swarm and attack the army ant. T ey save the nest. Talking with smells is nothing to sniff at!
Other animals use smells to mark where they live, or their territory. A tiger is a good example. It usually lives alone. It doesn’t want to share its space with other tigers. It doesn’t want to compete for shelter, water, and food. So the tiger walks around the edges of its
territory. It rubs its cheek on a tree. It stands on its back feet and digs its front claws into the bark. It backs up to the tree and sprays a musky substance on it. T ese actions leave something invisible. T ey leave a smell. T e smell comes from glands in the tiger’s cheek and near its tail. A tiger even has glands tucked between its toes. All these smells send a message to other
tigers. T ey say, “T is place is mine. Stay away.”
This tiger rubs its cheek on a tree to leave a scent. Its smell tells other tigers to stay away.
Leafcutter ants follow a trail of smells.
6 NATIONAL GEOGRAPHIC EXTREME EXPLORER
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