Entomology (Study of Bugs):

Entomology (Study of Bugs): ants, dead ants, species of ants: "Ants carry other ants for a few different reasons...

1) When an ant dies in the colony, another ant will pick up the dead ant and carry it to a 'trash' area of the nest. This trash area may contain dead ants, remains of insects eaten for food, bits of grass or other particles in the nest that are considered by the ants to be 'trash.'
2) Ants get parasitic diseases and fungal diseases that are contagious and may be passed to other ants. Sick ants are carried as far away from the nest as possible to reduce the chances of introducing a disease into the colony.
3) Some species of ants are very territorial and will fight with other ant colonies (same or different species) for territory. Ants get killed in these battles and the victors will carry the dead ants around and sometimes place the dead ants around the entrance of their nest."

Heck...we have so many of them around that we might as well study them...lol. I was noticing an ant carrying another dead ant around and decided to look it up (see answer above).