Every monsoon brings out millipedes by the thousands — the small black and yellow flat millipedes, the slim brown ones with a red stripe running down their backs, and the large 20-centimetre browns.
As anyone who’s stepped on one knows, they smell awful. Millipedes exude cyanide gas and a cocktail of noxious chemicals such as benzoquinone to deter predators.
Two years ago, we bought a pair of emu chicks to add to our menagerie, and the breeder warned they were dumb, likely to eat stones, plastic pieces, bits of wire, or anything else. He advised keeping them in an enclosure until they were six months old.
When they were old enough, Rom and I cleaned a paddock of stones, sharp twigs, shards of broken terracotta planters, and wood chips. We let the birds loose and watched as they plucked flowers and picked over dry leaves. Unexpectedly, one chick bolted down a long, snaky thing. “Did it just eat a millipede?” I asked Rom in horror.
He didn’t know; he was watching the other bird. But the millipede assassin seemed none the worse for it.
When a black and yellow flat millipede crossed the path in front of an emu chick, I held my breath. The emu examined it, tilting its head to the side and giving one eye an unhindered view. Shaking its head seemingly with distaste, the bird wandered away. Rom looked at me as if to say, “You must have been hallucinating.”
A butterfly flew past, and the chicks stumbled after it, their large feet getting in the way. Watching their clumsy and comical antics, I relaxed.
Then one of the emus swallowed a large brown millipede in plain sight. “Did you see that?” I demanded. Rom had and was concerned. An hour later, the emu chick still hadn’t keeled over. Instead, both competitively bolted down the large millipedes like I would brownies.
I spent that evening on the net and identified the millipede as possibly being Spinotarsus colosseus; I named it Colossus for short. Many species of millipedes in Australia, where emus originate, look similar to Colossus. However, not one website mentioned emus eating millipedes. Nor could I find out if Colossus was toxic.
Wedge-capped capuchins of Venezuela and black lemurs of Madagascar use millipedes as ready dispensers of insect repellent. The monkeys nibble on the leggy invertebrates a little, and rub the benzoquinone exuded by millipedes all over their fur to ward off mosquitoes. The chemical is many times more effective than any manmade, DEET-containing, insect repellent.
Benzoquinone makes the primates drool profusely and their eyes glaze over, leading some wildlife documentary producers to speculate that they were getting high.
Although capuchins and lemurs live on two different continents, they use millipedes of the same family, Spirostreptidae, which is closely related to Colossus. I wondered if millipedes were so poisonous, why the emus weren’t affected.
Colossus millipedes disappeared from the paddock within weeks, while the two other species sedately crawled about. I figured although these unmolested species were smaller than Colossus, they probably packed a toxic punch. Perhaps, the emus did know what was safe to eat.
In May this year, we celebrated the emus’ second birthday. I was relieved we had no medical emergencies when the Colossus assassins were growing up.
Two weeks ago, I had cause for renewed concern. Amba and Chola, our three-month-old puppies began gobbling up the flat millipedes. Unlike the emus, they breathed that unpleasant crushed millipede stink in our faces. But like the emus, they suffered neither poisoning nor indigestion. Nor do they seem to be getting high. We don’t know if these millipedes are hardly toxic, if dogs and emus are immune to them, or if eating millipedes confers some advantage.
But the pups won’t touch Colossus or the red-striped millipede. Perhaps Colossus is far too large for them. While the red millipede may not be named Xenobolus carnifex for nothing — carnifex means public executioner in Latin.