I am sure we envied Chi'en Lee and Bob Cantley and dreamed to be with them to look for the exotic nepenthes species in Borneo and Sumatra. And if you go deep into the humid forests and jungles of South East Asia, you you discover more than just nepenthes. You will find things sticking onto you. Yes! LEEEEECHES! (see the bottom pic of JCPS trip to Mulu)
Almost the entire visitors' book to Taman Negara (National Park) HQ is devoted to locals and foreigners encounters of the slimy things. They can be very tiny when they start on you but end up as big marbles when they finish. Somehow, they can sneak thru your socks and sneakers without you knowing it and start feasting around your piggies and ankles. At times you can find them crawling up your legs. If you pull them off before they finish feasting on you, the little wounds will continue to ooze out blood. That is because they have secreted an anti-clotting agent into your body. Good for high blood pressure.
Unless you are an ex-marine or a naturalist like Jeff Corwin (I have seen an Australian lying on his body to photograph mushrooms and have 20 or more leeches feasting on him) feeding leeches is something you want to avoid unless you are participating in an episode of Fear-factor.
So don't forget to bring your leech socks when you come over. If you can't get one from your trekking specialist store, let me know and I will help you get a pair.