This tiny Monarch caterpillar hatchling is probably about 1 day old and only about 2mm long. When it hatched, the first meal it ate was its egg shell. Next it ate the tiny hairs on the back of the leaf. This little caterpillar has already eaten a small hole in the leaf. Within the next 2 weeks, it will eat many leaves. The tiny black bumps on the top near the head and back end will grow into the "whiplashes" (antennae). In 2 weeks this little caterpillar will molt its' skin 4 times (the period between moltings are called "instars") and eat and poop a lot! Monarch caterpillars gain 3000 times their hatching weight by the time they are ready to become a chrysalis. I tell my students if they grew at the same rate as these caterpillars, by the time they became teenagers they would be as big as a school bus and weigh as much as 2 female elephants!