Where ants in pants can make you scream

THE jungle is full of dangerous creatures. But there was one I came to fear more than any other during my time in Costa Rica. It wasn't the tarantula that crawled out of my luggage, the cayman that lurked in the river behind my lodgings or even the baby boa constrictor that slithered into camp. What I feared was far more sinister: ants.

Ants are simply everywhere in Costa Rica. Leafcutter colonies march across paths, tiny ones find their way into your backpack and bright red fire ants seem to be swarming in wait wherever you go.

Cute animated films such as A Bug's Life and Antz portray ants as trendy little critters with personality. Unless one has bitten you, you might be fooled into believing they are harmless. They are not.

An ant's natural defence when threatened is to spray formic acid on its victims. First they bite, then they spray the wound on your skin. While the spray of one ant might just cause an itch, the trouble with ants is that they don't fight fair: when they declare war, it is a thousand to one. The effects can send people into shock or even prove lethal.

When the little guys got me, they got me good. Ants were a constant battle at the turtle conservation project for which I was volunteering. On a remote Costa Rican beach fringed by jungle, ants would burrow into the turtle hatchery in the sand, feeding on the eggs and spoiling the nest. Any ants or ant trails would be swiftly doused in boiling water in an effort to protect the 40-80 endangered baby turtles that might still emerge from the nest. Nightly shifts at the turtle hatchery ended at 2am. It was rewarding, if sometimes tiring, work and to stay awake, often chewing on sweets was easier than boiling a pot of coffee in the kitchen 500 metres away.

Hiking back after finishing my shift, I popped one final sweet into my mouth, cramming the sticky wrapper thoughtlessly into the mesh pockets of my safari pants. Inside the dorm, I changed into my pyjamas, leaving my pants crumpled in a pile on the floor.

Come 6am, nature called. I reached sleepily for the pants in the pre-dawn darkness, pulling them on. First I felt the burn. Then I screamed. A dozen heads shot up from their bunks.

"I've got ants in my pants!"

While I had slept, the ants had smelled the sugary sweet wrapper and descended on my pants in their thousands, turning the yellow pine floorboards into a sea of black.

Slapping, scraping and swearing at the dozens that clung to my thighs, I ran in my underwear to the showers to howls of unsympathetic laughter from dorm companions. For 10 minutes, I let the ice-cold water run down my legs, plotting my revenge on the ants while the acid burned.

Sure, I was an animal lover. But I'd been pushed too far. This was war. My legs were covered in red-and-white polka-dot welts. I returned to the dorm with my arsenal - a 750 millilitre can of pure, poisonous bug spray.

Revenge was sweet.