Yep! Many, many little caterpillars have made the tops of my carrots home recently.
Named black swallowtail these caterpillars love the tops of plants such as carrots, dill and even fennel. With the bright wild flowers I had growing near by the butterflies decided to make the carrots home and laid eggs (that I didn't notice) on the underside of the plant. At first seeing all these caterpillars can be over welcoming and worry some but no need to fear! As long as you do not mind them once they grow into butterflies they are beneficial to a garden. These butterflies see colors (like red) that bees do not see witch attaches them to more plants making them great at pollinating.
I find growing extra is always best. That way you have some to use and some just for them to eat. It is a great learning experience for kids and adults alike. The eggs of these butterflies are white, once hatched they are black and take on a spiky look. After awhile they turn a mix of black, yellow, and green and take on more of a round look before making a chrysalis. Now if it gets to cold out for them to fully make it to a butterfly they will enter a diapause stage and wait till next spring to emerge.
These caterpillars can be brought indoors for kids to watch change, just make sure to included food for them to eat. We will see what happens with these little guys as time goes on. Hopefully they will grow and not become a birds snack. :)