THESE ANTS ARE HAVING A BALL
Around the home, ants are tiny annoying pantry raiders. On the lawn, they can be toe-terrorising sting-deliverers. But generally, the average human reaction to an ant is negative. We try everything we can think of to exclude ants from our houses. But out in the bush, ants lead a rather more cooperative life with other species.
This group of small black ants with distinct fuzzy gold hairs on their abdomens, cluster around a twig on a small acacia. Deep inside the ball, not visible in the shot, is a pupa of some kind. We took this photo after heavy rain, so it’s possible the ants are protecting their own young, high and dry and away from muddy ground.
But elsewhere on this same acacia, ants patrol the stems and twigs, knocking off some pests but actually tending to the wellbeing of others.
The larvae and nymphs of various leaf-hoppers, aphids and other sapsucking species often shelter under waxy shields or “scales”. A strange byproduct of these insects is a substance called honeydew.
Honeydew is created in an almost hilarious process. When the sap-sucker penetrates the plant with its mouthparts, the pressure released is so huge (relative to the tiny insect), that liquid is forced into the bug’s digestive system and displaces anything already present. This partially-digested material, rich in sugar, shoots out of the insect’s anus. There’s no politer way of putting it.
Some species have hairs or other structures that capture the honeydew, allowing ants to collect it straight from the aphids bum, as it were. Others can take the pressure, as it were, but allow ants to “milk” them by pressing on their abdomens with legs or mandibles, to extract the honeydew.
It’s a complex ecosystem of a dozen species living in an almost-symbiotic relationship on a single, fairly small plant.
As for our precious gardens, it’s true that ants can hurt a tree or bush that’s already sick in some way. But if the plant is doing well, growing steadily and getting plenty of nutrients, ants crawling up and down the stems and over the leave are actually patrolling for nasties, not trying to steal your lemons.
Meanwhile, this ball of ants on an unremarkable acacia sapling in a Blue Mountains reserve, will continue to protect their young until the ground below dries out. Then they will painstakingly march their larvae and pupae back down underground, just like it says in the song.