Mosquitoes
Mosquitoes are rarely encountered in relatively undisturbed forests. They are most often encountered when the trek passes through plantations or where campsites are littered with rubbish. While the itch from the bite is irritating, some species of mosquitoes found in South East Asia are carriers of malaria and dengue fever. Fortunately, mosquitoes are also the easiest to fend away with mosquito repellent or mosquito coil.
Leeches
Contrary to popular beliefs, leeches can be found in forests trail where the water source may be a distance away. Leeches commonly found in Malaysia forest are about one to two centimeters in length and are brown. A little less common is the locally known tiger leech which can reach a length of five centimeters, and is distinguishable from its brown and orange bands running along its length. Unlike mosquito's bite, leech bite is not itchy (unless infected) but they leave a bloody mess at the bite site as the powerful anticoagulant in the leech saliva prevents the wound from sealing up for a few hours. Fortunately, the blood flow is usually slow and thickens after ten to fifteen minutes. It is best to leave the wound site alone and not try to remove any "excess" blood clot that covered the wound until the following day. Otherwise, the blood flow may start again and it will take a while to stop the bleeding.
There are a few methods of preventing leech bites. Some local guides rub salt on their feet to fend off leeches. Insect repellent containing DEET in the form of cream has also been shown to be effective in keeping the leech off. Wearing leech socks that covers your feet to your calf provide a barrier although a persistent leech may still crawl up your body in search of exposed skin.
In the unfortunate in event of finding a leech on your exposed skin, you may try to flick it off if it has not bite. You can see its small head searching and feeling around. There are several methods of getting the leech to dislodge when it is sucking. Vinegar solution, salt, tiger balm, medicated menthol oil and some insect repellent has been shown to be effective. Use of hot ambers from mosquito coil or heated lighter head will also work but you may feel a sharp but short pain during application.
Sandflies
This is probably the most irritating blood suckers found in Malaysia treks. Fortunately, it is not as common as mosquitoes and leeches. Sandflies are small biting flies less than 0.5 mm and are almost impossible to see as a result. The bites from these flies are very itchy and they take days to recover. Sandflies are usually found in isolated area and are only a problem when they happen to take residence at campsites.
Keeping sandflies away is more difficult than the other two blood suckers. Reducing exposed skin by wearing long trousers and shirts is probably the only commonly agreed method of keeping them at bay. Other recommendation includes using smoke and insect repellent containing higher concentration of DEET although opinions differ for the later method.
