Here is a caterpillar I found while making my rounds watering the plants at work. It is a black swallowtail larva and looks pretty close to entering its pupal stage. I found it resting on a dill plant, probably digesting all the food it ate. The butterflies like laying their eggs on carrot relatives including dill plants and also do them a favor by pollinating their flowers. When disturbed, the caterpillar ejects this brightly colored, forked "tongue" from behind its head. This is the osmeterium. It's a special gland that releases a foul smell to deter predators.
That is all for now.
Class dismissed.
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From @proto26