These Western Thatching Ants were trying very hard to get this dead insect back to their nest, which is an above-ground mound of dead plants.
According to Washington State University Extension Bulletin 0929, these ants are considered beneficial since they eat so many other insects. The Bulletin also says:
An interesting phenomenon demonstrated by thatching ants, as well as other ants, is the habit of “herding” and maintaining aphid colonies on trees, shrubbery, and weeds.
Think about that. Is this any different than humans and cows? The ants have aphid farms!