More than 60 people, many in the under 10 category, were entertained by Ajay Narendra. Ajay provided a fascinating glimpse into the life of ants. Starting with some facts and figures, ~12 000 ant species world wide, ~1500 in Australia, the biggest ant in the world is sausage ant of the Amazon, up to 55mm in length, while a species of bull ant around Alice can grow up to 40mm.
The first ant nest we looked at in detail was a meat ants’ nest. The nest itself has multiple entries, which is unusual as most species of ants have only one nest entrance. The exposed nest surface was perhaps 2 m in diameter but Ajay told us it could well be 4 metres deep and house up to a million workers! Each worker ant (all females) have a chemical signature that is unique not only to the species but to the individual nest. This signature allows the workers to recognise their fellow workers and chase off any intruders. Meat ants prey primarily on dead animal and insect life and have been known to reduce a possum to bones in 10 days or so. More generally we heard that ants generally zig-zag because they are following chemical trails laid down by other ants so they use receptors on the antennae to stay on the trail. We also learned how when the queen mates, she stores the sperm from the male (or males) in a special cavity in her body and she may keep them stored there for up to 18 years until conditions are deemed favourable to produce males!
We also looked at Jack jumpers, or Jumpin’ Jacks. One of only 3 species of ants that jump in the world, these medium sized critters are also the second most poisonous ant in the world – their venom has been know to induce anaphylactic shock. Recognised by their large rear legs (they look remarkably like a grasshopper legs) and elongated, serrated yellowish jaws these highly aggressive ants can jump 2-3 times their body length repeatedly and will chase intruders from their territory or sting them with their stinger located in their abdomen. One of the species of ants that are active during the day, the Jumping Jacks are actually rather primitive not using any form of chemical trail marking to help other individuals find food, relying on individuals to forage independently.
We also found an ant-mimic, hemipteran bug (members of the insect order Hemiptera, ie true bugs), which with its green metallic sheen looks quite similar to the green-headed ant, a common ant on Mt Majura. As is the case with wasps, many insects have evolved to look like something their not, in this case an ant, probably to scare off predators.
The facts kept flowing, how sugar ants use a form of tandem, “tap along” recruiting. How another ant we looked at wasn’t a sugar ant but a nocturnal relative. This particular individual was a soldier ant and had long jaws with sharp front teeth, and blunter back teeth so it can carry eggs and grubs safely.
Ajay related how once, when studying ants he had been surprised by elephants and had to spend two days in the tree he climbed to escape the protective mother. To judge from his knowledge and enthusiasm, one can only imagine that so long as there were ants in the tree, this wouldn’t have been a hardship.
Peter Miller
25 March 2007
