The most important things I learnt in Thailand.

Never, ever put your hand (or your foot) into a dark place before (you are sure) nobody else is already happily ensconced there.
This goes for your clothes, hanging on the line or lying on the floor. Your bed – shake blankets and pillows before every use.
Check windows before opening in case large green cicada-like insects with obscenely long legs are out there, waiting.
Shine a torch on the ceiling to be sure no large wasps are laying eggs. (Although the geckos eating them are less of a worry.)
Look into the toilet, and the bathroom in general to ensure frogs have not taken up residence. Have a really, really good look inside the toilet water, the small pail with a handle in a large container of water for pouring in the toilet may just have a resident spider that refuses to be re-homed that insists on running up your arm when you want to flush the toilet.
And when you take a seat for dinner, check above your head – those ants crawling on the beam may not be much of a threat but once the lights go on and large beetles are smacking excitedly into the light these ants may become dislodged (and angry) and end up in your plate :-)