·         Exploring the importance of decomposers.

·         Investigating the social interactions of ants.

BACKGROUND:

Ants are common insects, but they have some unique capabilities. More than 10,000 known ant species occur around the world. They are especially prevalent in tropical forests, where they may be up to half of all the insects living in some locations.

Ants look much like termites, and the two are often confused—especially by nervous homeowners. However, ants have a narrow "waist" between the abdomen and thorax, which termites do not. Ants also have large heads, elbowed antennae, and powerful jaws. These insects belong to the order Hymenoptera, which includes wasps and bees.

Enthusiastically social insects, ants typically live in structured nest communities that may be located underground, in ground-level mounds, or in trees. Carpenter ants nest in wood and can be destructive to buildings. Some species, such as army ants, defy the norm and do not have permanent homes, instead seeking out food for their enormous colonies during periods of migration.

Ant communities are headed by a queen or queens, whose function in life is to lay thousands of eggs that will ensure the survival of the colony. Workers (the ants typically seen by humans) are wingless females that never reproduce, but instead forage for food, care for the queen's offspring, work on the nest, protect the community, and perform many other duties.

Male ants often have only one role—mating with the queen. After they have performed this function, they may die. Ants communicate and cooperate by using chemicals that can alert others to danger or lead them to a promising food source. They typically eat nectar, seeds, fungus, or insects. However, some species have diets that are more unusual. Army ants may prey on reptiles, birds, or even small mammals.

PROCEDURE  

1.    Prior to activity: set in the garden a petri dish with maybe sugar, protein, carbohydrate and water. To learn about the eating habits of ants, you can place several types of food in separate, flat container lids. Using a permanent marker, write on each lid the type of food it will hold. Be sure to include these three different types of foods:
      •Sweets, such as candy, brown sugar, or fruit juice
      •Proteins, such as meat, cheese, or milk
      •Carbohydrates, such as crackers, or cooked rice or pasta
      •Also, set out a lid containing plain water. That will serve as your control. The foods are the variables

NOTE:  Prior years have had problems finding ants to look at on the school grounds so it is important to test whether you can get ants by setting out ant traps described above a week or so in advance of the lesson.   If you can’t find ants at school, you should capture some ants from your yards ahead of time and keep in a covered container for the class so students can see real ants.

2.    Read storybook, "Ant Trails."  Discuss the importance of ants.  Go over the parts of an ant.

3.    Hand out the life cycle of the ant worksheet with the models.  Go over each stage. Please note they go through complete metamorphosis.

Eggs:  After mating, a princess ant is considered a queen ant.  She finds a good nesting site to start a colony, where she lays thousands of tiny eggs.  She won’t leave the nest until the first generation of worker ants are ready to search for food.  Once her colony is established, a queen ant may lay thousands of eggs each day.

Larva:  Eventually, ant eggs develop into larvae, which resemble tiny pieces of rice.  They have no eyes, only a mouth and they are fed by worker ants that bring food to the nesting site.  It takes between a week and a month for eggs to turn into larvae, depending on the species.

Pupa:  A few weeks to a month after becoming larvae, the growing ants will be ready to spin cocoons, called pupae.  Within a week or so, pale yellow ants will emerge.  They turn their normal color once their exoskeleton hardens.  A queen’s first batch of ants will be smaller because they have not been fed by other worker ants within the colony.

Ant:  Once its exoskeleton hardens, an ant is ready to begin supporting the colony. Worker ants are by far the most common, but some ants can also develop into soldier ants, drones, or princesses.  The worker ants have distinct tasks, including caring for eggs, finding food, or expanding and maintaining the colony.

4.     Examining real ants.  Go outside where you put the “ant bait” and see if the ants were attracted to any of the food sources.  Which food source was most popular?  Also look in other areas of the science garden or on school ground, especially near compost area.  You can call it an “Ant Scavenger” Hunt.  Have the students look at what the ants are doing.  Are they walking in a line or milling about?  Are they carrying anything?  If so, what?

If there are no ants outside you can look at ants in the lab using ants you captured at home.  Put a couple ants in covered petri dishes (at least one for pair of students) and have students look at the ants with a hand lens.  Have them try to see all the parts of the ants and they can draw an ant on their ant worksheet.  You can also put multiple ants with some dirt in glass or clear plastic jars or containers so students can see more ants interacting with each other.  What are the ants doing?  

You can also set up a couple of microscopes at the back of the lab that the students can take turns using so they can see more detail.  Put down a drop of honey in the petri dish to keep the ants in place so the students can see them.  Otherwise the ants move so fast out of the field of view that the students get frustrated. 

5.    If rainy, you might want to capture a few ants  in a petri dish and have the students look under the microscope.