By Bob Dispenza, Park and Education Manager, Allen County Parks, Fort Wayne, IN
Ants have invaded popular culture in a way few insects have. Everyone has heard of “busy” bees and “hard-working” ants (they are actually related to each other). Ants have starred in a number of movies and TV shows, not all of them positive:
"A Bug’s Life"
“The Zanti Misfits” episode of “The Outer Limits” (actually aliens that looked like ants)
Ants have a reputation as hardworking, industrious, caring (for their young), strong, brave, “intelligent,” and usually peaceful unless threatened. Proverbs 6:6-8 says “Go to the ant, O sluggard; consider her ways, and be wise. Without having any chief, officer, or ruler, she prepares her bread in summer and gathers her food in harvest.” Proverbs 30:25 adds “… the ants are a people not strong, yet they provide their food in the summer…” Ants are the wise ones in the Aesop fable “The Ant and the Grasshopper.”
There are 12,000 to 14,000 species worldwide, making up 15-20% of terrestrial animal biomass (more than vertebrates). Native ants are only lacking in Antarctica, Greenland, Iceland, Hawaii and a few other islands. The largest is the male siafu ant (Dorylus species) of the tropics at 40 mm long. The smallest is possibly Oligomyrmex yamatonis of Japan, with workers at 1 mm (about sand grain size). It would take 100,000 of them to weigh 1 gram or 2,835,000 to weigh 1 ounce.
The jack jumper ant of Australia (Myrmecia pilosula) has only a single pair of chromosomes (males have only 1 chromosome) – the smallest number of any animal. They are considered primitive ants with small, unorganized colonies. They hunt individually by sight, but their stings can be fatal to humans. The most painful sting belongs to the bullet ant of Central and South America (Paraponera clavata). We live in an uneasy truce with ants, and most hits from an Internet search will turn up sites that tell you how to kill them.
Ants are designed to take advantage of food sources quickly without the energy-consuming necessity of flight. So they often show up first at the picnic. They lay a chemical trail down as they forage, allowing other ants to follow them to new resources.
The “society” of ants is divided up into “castes”:
Sterile females have two sets of chromosomes and are the workers of various types, soldiers, millers, and storehouses (repletes that hold extra resources). Some ant duties are determined by size (the larger ones usually functioning as soldiers) or age (the youngest start with nursery duty or as queen attendants, moving to nest maintenance and foraging as they get older). Workers live one to three years.
Queens are the only ones able to produce workers and other castes. Some sterile females can lay eggs, but they produce only drones. Queens can live for up to 30 years.
Kings (drones) have only one set of chromosomes, and are only present for a short time during the swarming season, when new kings and queens fly off to start new colonies. Drones die after mating.
Ant weapons are mainly jaws (which can be quite powerful) and stings (modified egg-laying organs) or sprays (some can spray acids or other irritants). Some tropical ants have jaws large and strong enough to serve as surgical sutures. They are made to bite the edges of the wound together, then the body is taken off and the head left to hold the wound closed for several days as it heals.
Ant strength may seem phenomenal, since they can lift 5 times their body weight or more. But they are subject to the square-cube law. Muscle strength relies on muscle cross section (2 dimensional) and muscle weight relies on volume (3 dimensional). Every time an ant’s size is doubled, its strength goes up 4 times while weight goes up 8 times. At our size, the ant could only lift 2% of its body weight.
There is just too much interesting about ants – see Part 2 next time.