Meet the caterpillar stage of the silver spotted skipper (Epargyreus clarus).  It is not uncommon to catch a few of these while sweeping soybean fields for insects.  Although the larva is a foliage feeder, it is not really considered a pest because it rarely, if ever, occurs in numbers high enough to cause economic damage. The head capsule of large larvae is typically maroon in color, but it may look black on small larvae. The fat body, dark head and eye spots (not really its eyes) give it a unique look.  Thus, I usually get several phone annually from curious callers.  The caterpillars will often make shelters by webbing leaves together.

You might recognize the butterfly, a skipper, belonging to the family Hesperidae (pictured below).  This species is widespread in the U.S., and primarily feeds on plants in the legume family.

Photo by Tony Wootton