Thailand has a few dangerous animals. The most common menace is stray dogs, which frequent even the streets of Bangkok. The vast majority are passive and harmless, but a few of which may carry rabies, so steer clear of them and do not, by any means, feed or pet them. If they try to attack you, don't run, as this will encourage them to chase you as if you were prey. Instead, try to walk away slowly.

Monkeys may be cute and friendly, but in any area where unaware tourists have corrupted them, they expect to get food from humans. They can be very sneaky thieves, and they can bite. As with dogs, you won't want to get bitten, as they carry diseases and viruses. Most urban areas do not have "stray" monkeys, but Lopburi is famous for them.

Venomous snakes can be found throughout Thailand, hiding in tall brush or along streams. You're unlikely to ever see one, as they shy away from humans, but they may bite if surprised or provoked. The best course of action when confronted with an unknown snake is to stay still until it leaves. The Siamese crocodile, on the other hand, is nearly extinct and found only in a few remote national parks.

Monitor lizards are common in jungles and can sometimes be found in urban areas (Bangkok in particular). Despite their scary looks, they are generally afraid of people and normally try to avoid them. Monitor lizards are protected species, i.e., it is illegal to hunt them, injure them, and keep them as pets. Opinions on monitor lizards vary in Thailand; some people believe that they are auspicious, while many others do not like them, viewing them as dirty, unclean animals. A superstition that some Thai people believe in: if a monitor lizard enters your home, good luck will come your way.