Name These Tiny Creatures!

On a recent trip into the rainforest, we came upon these small creatures. They were each approximately half an inch long, red colored, and would walk in a line. We saw them cutting and carrying large bits of a leaf on their backs. If you picked up the leaf, their legs would keep moving as if they were on the ground!

These look similar to creatures we're very used to in the US, however, we're certain we've never seen this specific type before. Try and be specific, and NAME THAT CREATURE!

NTC