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Hazards of Trail Running in Thailand Tropical Rainforest – Asia

Hazards of Trail Running in Thailand Tropical Rainforest – Asia

Rainforest Running Trail - Thailand

Besides the 95F weather with 90% humidity, roots, thorns, and slippery rocks, there are some other hazards faced while running mountain trails through the rainforest in Thailand, Laos, Cambodia, Burma, Malaysia, Vietnam, or anywhere you live. The USA, Canada, and Australia have some of these same hazards.


Dogs are probably the worst threat you’ll run into. I’ve had days where I see no dogs at all, and then days when I’ve been bothered by forty dogs in a pack on a remote hill with no other humans beings around for help.

Luckily in Thailand the dogs are:

1. Not that big.

2. Not that ferocious – there are few rottweillers, pit bulls, shephards, etc.

3. Not that bright.

Dogs in Thailand inevitably fear two things. Sticks and rocks. Pick up whatever is at hand and threaten the dog with it, before it takes a mouthful of your leg. I know you love dogs. Me too. Dogs in Thailand don’t like foreigners because we look different. We probably smell different. Apparently they want to see if we taste different.

The stick trick works in 90% of cases, it backs the dog(s) off to around 10-15 feet. This gives you some time to find some rocks. Big rocks preferably. Start wailing the rocks toward the dogs and they high-tail it away from you quick. Nearly every dog in the country has been hit by a stick and hit by a rock. None of them want to repeat it.

When the forty dogs came after me on the hill I picked up a big stick. They didn’t stop running toward me, but they did slow down a lot. They were still coming after me and barking though, so I started throwing rocks at them. Gradually they all got the idea and turned away. I was amazed really. Dogs in a pack are nothing to mess with, but if you can scare them with rocks before they get too close, you’ll probably be OK.


I know, caterpillars, right? Seriously. There are caterpillars that have stinging hairs that feel like blow torches when they touch you. I had one yesterday on my ankle, which in part prompted me to write this info-bulletin today.

It starts out as a tiny burn, which escalates into a full on bonfire. I looked at my ankle when I felt it yesterday, and couldn’t see anything. The pain was unmistakeable though. Be careful about brushing leaves as you run by. The worst pain would be to get a caterpillar in the eyeball. I’ve had them on my arm, leg, back (I went under a fallen tree and I brushed it with my lower back – ouch!), and now ankle. The pain doesn’t last forever, but you’re in for a good half hour of searing pain.


I go hunting (herping) for snakes and other wildlife at night. I’ve seen scorpions of all kinds, but they are always on the ground, and usually under something. There are about eight species of scorpion that I know of in Thailand. A couple of them like to climb vines on the trail I run.

Last week I was clearing part of the path from this massive growth of thorn bushes and vines when I saw something moving up the vine. Wow, a 3 inch brown scorpion. I couldn’t believe it. I made a mental note not to touch the vines in that area any longer.

Yesterday I was running down the mountain, grabbed a vine in a different area to help slow me down as I descended a steep section.  Something crunched under my thumb as I grabbed the vine, then an immediate sting and it dropped to the ground. OUCH. Scorpion got me. Same kind I saw on the vine the week before. Guess they got revenge on me at last… Here’s me eating one in a video.


There are some sting-less bees in Thailand, they are small and look weird as they fly through the air. They don’t swarm when you run through them. They don’t sting. They make little tubes that stick out like straws on trees and in limestone rocks.

Then there are many other species of bee that do sting. I met one yesterday. Yes, no kidding, I was stung by three beasties yesterday on that one 6 mile trail run! I was cutting away some vine from the trail and felt a sting on my shin. WHACK! I smacked that bee into the next life. Then I ran my ass off before his friends found me.

If you are running through the rainforest and you hear a hum, you can bet it isn’t Pooh Bear singing his silly songs. Just turn around and go back the way you came because bees are nothing to mess with. Recently two Buddhist monks were attacked by a swarm and they are in critical condition in the intensive care unit of the hospital.

Over the past couple weeks we have had these gigantic bees coming around our front porch at home. I killed one. I don’t like bees. Almost instantly, there were eight to ten more bees there flying around me like they were going to attack. I quickly went in the house where I was trapped for 40 minutes until the pheromones went away enough that the bees relaxed and went elsewhere. Bees, when aggravated, release these pheromones that float through the air and instantly alert other bees that they need to come and help attack something. Scary stuff!


Malaysian Sun Bears (Helarctos malayanus) and Asian Black Bears (Ursus thibetanus) are roaming the rainforests of Northern Thailand, a lot of Malaysia, and some other choice places. Though where I run doesn’t have them on the distribution map, I have seen some large scat and large undefined tracks in the mud. The national park I run through is big enough to have a bear. There are plenty of trees with smelly fruit on that mountain. I wouldn’t be surprised to see one.

The two bears mentioned are known to be extremely aggressive at times. I have yet to hear of someone attacked by one here in Thailand yet. I’m sure it has happened in the past.

Bears climb trees. Bears run fast. Still, if I see a bear and he comes after me, I’m running for my life. I think I can get down the technical trail at least as fast as it can, and hopefully with all this exercise I’ve been doing I am fitter than the bear and can wear it down over a kilometer or so. That’s my plan. You should have a plan too.

Oh, my other plan is that I would climb a thin tree – about 6 inches in diameter that was near some other trees. If that bear climbed the same tree, I would swing over to another tree beside it, and another one and another one. Bears cannot do that. I think it would tire of my shenanigans and go find some delicious honey to munch instead.


In theory snakes could be a problem. I’ve spent hundreds, probably a thousand hours by now in the rainforest on trails in Thailand and Malaysia and I’ve not been bitten by anything. Of course I watch where every step goes, but still… over all this time I could have stepped next to a snake I didn’t see and been tagged.

I’ve seen just a few venomous pit vipers on the trail during daylight hours during a rain shower. Just four. I’ve seen about forty other snakes during runs, but they were all non-venomous and of no danger at all. See my other site – for more information on snakes found in Thailand and Southeast Asia. Here’s an account of when i just missed stepping on a venomous pit-viper on a run in Thailand.

The only three snakes you’d have to fear in Thailand, and I think most or all of Southeast Asia are:

1. Cobras (Naja kaouthia; Ophiophagus hannah; Naja siamensis; Naja sumatrana). They are active during day and night. They flee when possible, like every snake, but they also are not afraid to hood up and strike either. Still, I see them infrequently in the forest, more so out on the streets and near homes – especially near the ocean.

2. Malayan Pit Viper (Calloselasma rhodostema). These are various brown colored snakes with triangle patterns on the back. They blend in very well with dirt and leaves and this is probably the biggest threat to anyone walking on a trail, through grass, or anywhere really, at night. During the day they are not active unless it is raining or very wet out. The problem with these snakes is that they do not move when they sense the vibration of a human walking toward them. They stay where they are until stepped on, then they dig their 1-2 inch fangs into your leg. I know one woman bitten during the day as she reached into greenery in her garden. It was a sunny day but she had the water on there for hours before and it was very wet.

It had to happen, eventually. Just last month I was running up the mountain, nearly at the peak, when I looked down horrified at where my food was about to strike the ground about 2 inches from a Malayan pit viper coiled up right on the path. Video here:

3. Russell’s Viper (Daboia siamensis). This is a large, usually grey or brown colored viper with white oval pattern that is common only near Bangkok and Pattaya in Thailand. This snake is probably responsible for more deaths in the world than any other snake. They are strong biters, have big fangs, and have strong venom. These snakes sometimes hiss when aggravated, so they are capable of a warning before striking. Not always though.


Golden Orb Weaver Eating Bird

If you are the first one on the trail you will be breaking spider webs with your face. Though I catch venomous snakes all the time, spiders flip me right out. I cannot take a spider on the face. I’ve had that happen half-a-dozen times while running the trails here. What I do now is I find a small branch with numerous branching twigs coming off it. I hold that in front of my face as I run. I still get spider webs in my face, but not spiders. The golden orb weaver (Nephila pilipes) spiders that I see most often on the trail are very large and they build the strongest web of any spider in the world. Here is a golden orb weaver eating a bird caught in its web.


I was running up the trail a couple years ago and all the sudden my left eye burned like someone poured battery acid in it. I cussed for fifteen minutes as my hiking partner marveled at my creative vocabulary. It burned intensely for about fifteen minutes. I rinsed my eye for ten minutes with water and eventually the pain died down enough that I could finish the hike. The only thing I can figure is that there was a bug on a leaf I ran by and it squirted me in the eye with its eye-disabling fire spray. It is a mystery to this day what it was. If anyone has any ideas, do let me know!

I know this covered the bad about trail running in Asia, there is plenty of good too – don’t let this scare you out of coming over for an ultrarunning race or trail running of any sort. I’ve run on the trail hundreds of times and have only had the few bad experiences listed here to complain about!


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2 thoughts on “Hazards of Trail Running in Thailand Tropical Rainforest – Asia

  • at 8:10 am

    Hey Vern,

    Thanks very much for sharing your post. I’m a competitive runner from NZ (live in Singapore), love running in forests but am struggling to find suitable places to run when I go on holiday in Asia. I’d love to go on a running holiday / camp if there was such a thing. Otherwise, do you have any location suggestions for (safe) forest running in Thailand and Malaysia? 10km long trails or more would be ideal.

    Thanks again

    • at 2:54 am

      I’m looking Dave… There is a nice hill climb in Penang – Penang Hill that I love. It’s about 800m elev climb, and dense forest. Quite a nice climb! Run down is nice…


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