The mystery skin disease turned out to be 'cutaneous larva migrans', a kind of worm that burrows into the skin and intends to enter the lungs where it lays eggs, which get coughed up and swallowed - to pass out in the animals faeces. Thankfully in humans this hanger on lacks the necessary enzymes to penetrate the body, and can only meander aimlessly just under the skin until it runs out of motivation. It can be treated with a drug called Albendazole.
The army ants have their own hangers on. In the photo, what appears to be an ant is in fact a small beetle, dressed up to look like an army ant, which lives its entire life in the mobile ant colony, feeding on the plentiful prey that the army ants bring back to camp.
Posted by ammonite at 10:50 AM