Picture this. You have finally escaped the city; work stresses and traffic jams are a distant memory. A nature escape feels like the perfect antidote to bring some balance back to your life; we’ve all heard that forest bathing is a proven remedy for anxiety. The highlight will be a magical walk through a tropical rainforest. The breathtaking canopy of ancient trees and graceful ferns draws your gaze upwards, their leaves adorned with what looks like diamonds, as little drops of water trickle down to the damp forest floor. Frogs are calling from moss covered rocks next to a gently bubbling creek. You’re taking it all in, mesmerized by the timeless majesty of the space, the peace, the tranquility. You feel your stresses melt away as you become absorbed in the moment, your forest therapy is kicking in.
Until. Until you look down at your leg which is covered in leeches, caterpillaring their way up on your bare skin, bloodsuckers at an industrial scale. We’ve all had a leech or two before, but this is truly the stuff of nightmares. You scrape them off as fast you can, smearing your leech covered fingers on the nearest tree, and look down to see another spooky armada inching their assent. You feel like Mickey Mouse in the broomstick scene from Disney’s Fantasia. The leeches are winning a war that goes on for hours. Deciding that avoidance is the only solution you hightail it out of the rainforest and complete yet another leech check. This is a two-person operation by this stage as some have made their way to the back of your thighs, disconcertingly close to your undies. Relief is in sight at last as you finally make your way to the campsite which is in a more open location less suited to the blood suckers. Victory today was not to have completed a 17 km hike but to have leech free legs! Your skin looks as though you’ve been used for target practice, but a clean-up and dry clothes offer great respite. Safely tucked away in your tent for the night, sleep comes easily….until. An all too familiar presence on your finger stirs you from your slumber. Yes, you guessed it. One more sanguivore.
If you can stomach that, read on. Many people find leeches revolting, but they’re actually highly adapted worms with some pretty cool survival strategies.
Fun facts about leeches:
- Two of nearly everything: Leeches have two suckers, two brains and multiple eyes and sensors to detect light, warmth and movement.
- Love is complicated: They are hermaphrodites, with both male and female reproductive organs, and mating involves the rather memorable ‘69 position’.
- Slow food: A leech can take several months to digest one blood meal and produce hundreds of eggs in a gelatinous cocoon then attached to a leaf or log.
- Not just forest foragers: Leeches are found across the world, in any damp place including creeks, wetlands and the sea. In Australia, they occur almost everywhere except arid zones, and will also attach to frogs, fish, turtles and birds. They are very common in the Hawkesbury in rainforests, creek lines and treescapes with a dense damp understorey.
- Perfect design: Their bite is painless; they then secrete an enzyme called hirudin which prevents blood clotting and is an anti-inflammatory. Their flexible body can expand enormously to hold the blood meal. A blood-soaked sock is sometimes the first sign that you've been leeched. Although it can look substantial, the amount of blood lost is usually small.
- From "panacea" to present: Leeches were widely used for 'bloodletting' to treat all sorts of conditions from cancer to mental illness, their popularity peaked in the mid 19th century. Today, microsurgeons may use them after finger re-attachment surgery to relieve blood build-up, while hirudin is also used in some anti-bruising treatments.
- Parasites with purpose: Why do we have leeches? Most parasites are just takers, not givers. Leeches do suck blood but in turn become an important meal for fish, birds and insects – completing a food chain.
How to remove one: Don’t panic. Gently slide a fingernail or thin, firm object under the attached end and flick the leech away. Avoid pulling or using salt, flame, insecticide or alcohol. All these strategies increase the risk that it will regurgitate its stomach contents into the wound which increases the chance of local irritation and infection. Removal works best when its deliberate and controlled, not a reflex reaction to the sight of blood.
Postscript. Despite the assault during a mass emergence of baby leeches, I did not die or even get sick. The area we were walking through had been dry for several weeks, and our hike coincided with rain. Leeches will remain dormant in leaf litter until moisture returns, then any passing warm-blooded creature is fair game. Despite their bloodsucking habit, leeches in Australia do not transmit disease. Many people will get itchy lumps from leech bites that can be managed with soothing creams or anti-histamines – ask your chemist for advice.
Leech fan or foe? Feel free to share your experiences in the comments below.
