Follow Me: How do Ants Find Food?

Problem

How do ants find food?

Materials

• 12-by-22-inch (30-by-55-cm) piece of white poster board
• anthill with a few ants on the ground around it
• 4-6 rocks or other heavy objects
• cracker
• binoculars

Procedure

CAUTION' Do not use fire ants for this activity. Also, be sure not to stand on or too near an anthill as you perform the activity. Take special care not to allow ants to get on your skin. If you are allergic to ant strings, do not perform this activity.

1. Lay the poster board on the ground with one end close to the entrance of the anthill,
2. Secure the paper with the rocks.
3. Crumble the cracker on the end of the paper opposite the entrance of the anthill.



4. From a distance, use the binoculars to watch the ants and cracker crumbs for five minutes or more.
5. Return after 1 hour and again observe the ants and cracker crumbs.

Results

At first, a few ants examine the cracker crumbs. Some may carry a crumb back to the anthill, but others return without crumbs. After a time, many ants go back and forth, carrying crumbs to the anthill.

Why?

You may have noticed that the ants touch their antennae to the ground as they walk. This is because the ants smell through their antennae. The job of some ants is to go out and find food. They use their antennae to find the food, then return to the anthill, some with and some without food. As they return to the anthill, their bodies give off a chemical that leaves a scent on the ground.

The first ants "tell" the rest of the ants about the food. Scientists believe that ants communicate by touching their antennae together. The other ants use their antennae to follow the smell given off by the first ants back to the cracker crumbs.

The scented chemicals that ants and some other animals, especially insects, produce are called pheromones. These chemicals are produced inside the insect's body and secreted (given off) to the outside of the body. Pheromones are chemical signals used in communication among members of the same species.

Let's Explore

1. Determine if the ants that find food give the other ants information about the amount of food and the number of ants needed to carry it. Repeat the experiment, placing three piles of crumbs, each twice the size of the next, at three different places.
2. How would the ants respond if the scent trail were disrupted? Repeat the experiment by placing a 2-inch (5-cm)wide strip of masking tape across the center of the poster board on the ground. After the ants have established a trail between the food and the anthill, remove the tape from the paper. Observe the behavior of the ants as they approach the disrupted area of the paper. Science Fair Hint: Take photos of the area around the anthill before and during the experiments and display them to represent the results.

Show Time!

1. The firefly is actually a beetle with a light-producing chemical inside its abdomen called luciferin. Fireflies use light flashes to communicate with each other. Each species of firefly has a different amount of time between flashes. Some female fireflies imitate the flashes of other species to lure the male fireflies close and then eat them.

   Experiment with imitating the flashes of fireflies with a penlight. On a night when you see fireflies out, determine how many seconds occur between their flashes. (The easiest way to measure 1 second is to say "one thousand one.") Turn the penlight on and off at the determined time. Flash the light at least ten times.

2. The Austrian entomologist (scientist who studies insects) Karl von Frisch (1886-1982) contributed greatly to our understanding of how bees communicate with each other. He discovered that the female bees who leave the hive and find food do different types of dances. The dances inform other female members of the hive of the direction and distance of the food. 

   Find out more about bee dances. Prepare and display diagrams showing the different dances and how they indicate different directions and distances of food sources. For example, the two different dances in the diagram indicate different distances. The circular dance means food is close to the hive, and the wag-tail dance means food is far from the hive. As the bee moves through the figure-eight pattern in the wag-tail dance, she waggles her head and tail from side to side. The farther away the food is, the faster she waggles. Find out more about bee dancing. Are the dances the same for each species?

Check It Out!

Female mosquitoes beat their wings to attract males. Find out more about courtship communication between insects.

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Janice VanCleave's Insects and Spiders
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