A caterpillar doesn’t have antennae. The projections at the front and back are called tentacles. (Business in the front, party in the back??)

Whenever I give a presentation about monarchs, I enjoy the question and answer period after I’m done. I might enjoy that most of all, because I love the interaction with my audience and because inevitably someone will ask a fun question.

Kids are best at asking the fun questions, even though they aren’t trying to be fun. They just have these wonderful curious thoughts and they aren’t afraid to ask about them. Recently, my grand kids were visiting and even though they know a lot about monarch butterflies (I’ve made sure of that!), they always have some questions.

While we were getting the kids ready for bed, there was a feeding frenzy going on in the monarch raising area, which prompted one of them to ask, “Do the caterpillars sleep at night like we do?” That led to comments about their ability to see in the dark, which led to a query about other body parts.

Caterpillars do sleep, but not like we do. They tend to take cat naps. (See what I did there?) Their rest period generally lasts from about 10 minutes, to a just a few hours. It doesn’t matter if it’s day or night. Each time they prepare to molt, they can remain inactive for a day or two until they crawl out of their skin, and then they turn around and eat it.

Even though monarch caterpillars have 12 eyes, called ocelli or stemmata, their vision is pretty poor. Mostly they can detect light and dark. They are better at detecting motion near them by feeling vibrations. They don’t have ears, but they will respond to loud noises thanks to fine hairs on their antennae. If you clap your hands loudly near a caterpillar, it will make a jerking motion and lift its head.

A monarch’s antennae are a great help to them when they’re moving around and especially when that last generation migrates to Mexico. In the club-like tips of the antennae, there are sensors that act somewhat like little GPS units. These are crucial during migration. They can still function with just one antenna, but if they lose both of them, they lose their sense of direction as well.

Monarch caterpillars have antenna-like projections both at the front and read of their bodies. These are not antennae though and they’re called tentacles. The longer ones located at the head help them in maneuvering around, while the shorter pair at the very back are a defense mechanism, meant to confuse and fool predators into thinking it’s the head end.

Both caterpillars and adult butterflies breathe through a network of openings along the length of their bodies called spiracles. If you look closely, you can see these openings as little slits on the sides of the caterpillar and even on the chrysalis. They’re hard to detect on the butterfly, due to the black color and the fuzziness of their bodies.

All the grand kids have held both the caterpillars and butterflies, but before they did so, each one asked, “Do they bite?” Caterpillars have a mouth with lips and jaws (called mandibles) with sharp projections that function like teeth. However, because of the sideways motion they use when eating, it would be very difficult to actually bite into human flesh.

The adult butterfly doesn’t get its nutrition from eating solid food. They don’t have mouths, but instead have a structure called a proboscis. The butterfly keeps it curled up when it isn’t in use, but if you look closely when they’re perched on a flower, you can see the proboscis uncurled with its tip down into the center of the flower, where the nectar is located. It functions similarly to a straw and they get the nutrients they need from the nectar they sip from a variety of flowers.

The most shocking question, which came from one of the boys (naturally), was this: do caterpillars eat their poop? The technical word for their poop is frass, and I’ve seen them crawl over it, pick it up and throw it, but I’ve never seen them eat it. They aren’t dogs, after all.