I can't really say that I like monkeys too much. Yes, they're cute and everything but they're also very unpredictable and can attack even if not intimidated. I'm talking about the macaques that like to speed up and down the rails along the boardwalk so watch out for them. You should also just take care with the orang-utans and try and face them all the time as they can grab things from you. Also keep an eye on young children.
Mosquitoes and Repellants
If you are the type who is easily bitten by mosquitoes, put on repellant prior to arriving at Sepilok. Apparently the smell of these repellants in your bags will arouse the suspicion of the wildlife, who might come looking for you!!