Ants march. Perhaps the most well-known marching ants are Army Ants or Eciton burchellii as scientists call them.
Army ants form huge colonies (300,000 – 700,000) and they need to "march" or migrate to find food. Most ant colonies send out "scouts" or individual ants that seek food and bring it back to the nest. Army ants don't work that way. Every few weeks, army ants enter a "nomadic phase" and leave the nest they've created. The entire colony sets out, en masse, to find a new area flush with food resources and a suitable nesting site. They march at night and camp during the day. When they have found an area where food is plentiful, they will begin their "stationary phase" and make a new, temporary nest.
Nest established, the colony sends out a swarm raid – a group of 200,000 or more ants – that take up an attack position resembling an open fan. This swarm position can extend over 15 yards. Army ants are blind, but by marching together, their numbers easily overwhelm any creature that may fall into their path. The swarm is seeking spiders, scorpions, insects and other ant colonies to kill and bring back for food. Regardless, if lizards, frogs, mice, or other creatures fail to get out of their way, the army ants will kill them as well, they just might not eat them. Army ants generally kill tens of thousands of animals a day!
Interesting Fact: Sometimes army ants will raid other colonies for slaves.