A primary rainforest with high humidity (often exceeding 90%), it provides the perfect year-round habitat for land leeches. "Leeches can be expected throughout the year in Sinharaja Forest, but more in the rainy season.  Few recommended precautions are: wearing ankle boots, use of insect repellant or apply liquid soap or salt on the exposed skin." (source)

On the core Nature Trekking trails that require a guide, the communication e-mail after booking states, "participants should wear suitable outdoor/sports attire for the activity, especially proper shoes and leech socks".

The Gunung Leuser National Park is notorious for its "tiger leeches." Unlike the common brown land leech, these have colorful stripes and are known for being particularly fast and aggressive. They are often found hanging from leaves at eye level, ready to drop on passing hikers.

Leeches are a natural part of the wet forest environment in the Greater Blue Mountains area, particularly after rain. The official park information provides the following guidance: "It is recommended to keep your legs covered during wet weather. Salt, tea tree oil, and toothpaste can act as repellents."

Lamington NP: Prevalent on most trails, particularly on wet, humid, or rainy days in the rainforest. Park website states: "Leeches are common in wetter areas. Insect repellent on your socks helps keep them away."