An Army on the March!
“We live in a Belizean village under development, surrounded by much vegetation. One morning at about nine o’clock, our home was invaded by an army. Ants came pouring under the door and through every crack, looking for prey. There was nothing we could do but vacate our home for an hour or two while the ants took over. When we returned, the house was completely clean of insects.”
FOR MANY PEOPLE living in tropical countries like Belize, this is a common occurrence and not entirely unwelcome. It is a way of ridding the house of pests such as roaches and other vermin. And it leaves no mess behind.
Interestingly, the ants spoken of here are called army ants because of their armylike life-style and activities.* Instead of building nests, these nomadic armies, hundreds of thousands strong, make temporary bivouacs, masses of ants interlocking their legs to form a living curtain around the queen and her brood. From the bivouac, raiding parties are sent out in long columns to seek food, consisting of insects and small creatures, such as lizards. The leaders of the raiding party also execute what appear to be flanking movements to trap prey. This phenomenon occurs when, having no scent trail to follow, the leading workers hesitate and hold up the advance. The ants in the rear inexorably press forward, and bulging occurs in other parts of the front line, resulting in a series of advances that suggest flanking movements.
Army ants operate on a 36-day cycle, going on the march for some 16 days and then remaining stationary for 20 days, during which the queen lays her eggs. After that, hunger causes the colony to go on the march again. Their marching columns, some 30 feet [10 m] wide, are edged by fleeing spiders, scorpions, beetles, frogs, and lizards and are followed by birds, which prey on these fugitives but apparently not on the ants.
Described as “instinctively wise” in the Bible at Proverbs 30:24, 25, ants are one of the marvels of creation.
This article deals with the Eciton genus of Central and South America.
[Picture on page 31]
© Frederick D. Atwood
[Picture on page 31]
Forming a bridge by interlocking their legs
© Tim Brown/www.infiniteworld.org