Bugs on the run

Insects are all around us, buzzing through the air, chirping in the grass and crawling across the sidewalk – but when it comes to running having six legs gives them extra stability! Let’s explore!

Materials

• Toilet paper tube and a few squares of toilet paper
• Marker
• Toothpicks

How to Get Started

Roughly divide your toilet paper tube into three equal parts. Draw an insect’s body with a head (top), thorax (middle), and abdomen (bottom) on each part of the tube.

Stuff your tube with the toilet paper, this will help your toothpick legs stay in place.

Can you make your model stand?

Insects have six legs that attach to their thorax, the midsection. The thorax contains strong muscles that help insects move their legs. If present, an insect’s wings also attach to their bodies on the thorax, for this reason the thorax is important for locomotion.

Insert toothpicks to the underside of the thorax portion of your cardboard tube one by one until you have added six legs total. After you insert each toothpick leg see if your cardboard insect can stand up.

• How many legs did you need before the tube could stand off the ground?
• How many legs were touching the ground once it could stand? How many legs are touching the ground after adding all six legs?
• What is the smallest number of legs needed to touch the ground to make it stand up?

Let’s explore even more!

Try adding many toothpick legs all over your cardboard tube. You may find it easier to remove the toilet paper squares for this part. Then, roll your tube across the table or the ground. Once it comes to rest, count how many legs are touching the ground.

What do you notice?

Now let’s observe a real insect

Three legs can form a stable structure called a tripod that is hard to tip over. What other objects use three legs to stand?

Insects have enough legs to form two tripods! When moving at fast speeds they will plant three legs on the ground while they move their other three legs forward. Having six legs allows insects to run at fast speeds while remaining surprisingly stable, this is known as a tripod gait.

Check out the Madagascar hissing cockroach to the right which was captured running in slow motion. Can you count how many legs are in the air and how many legs are on the ground as it moves?