Tag Archives: ptyas carinatus

Keeled Rat Snake – Ptyas carinata – Not Dangerous

Keeled rat snake from southern Thailand - venomous, but no effect on humans.
Keeled Rat Snake – Ptyas carinatus – Not Dangerous (not deadly)

Keeled Rat Snake (Ptyas carinatus / carinata)

Thais say: Ngoo noo

Length: These snakes can reach almost 4 meters in length, though they are much more common at the 2 meter length.

Range: In Thailand the keeled rat snake is found all over the country. I have found them in Krabi, Surat, and the Sisaket province, near Ubon Ratchathani.

Habitat: Lowlands and hilly rain forest type habitat primarily. The last 5 of these snakes I saw were all found at at less than 200 meters elevation, and in the forest on and just off hiking trails during the day. It is worth noting that the snake in the embedded video below was found at 100+ meters elevation climbing a limestone cliff.

Active Time? I have only found these active during the daylight hours (diurnal), though one was found thirty minutes after sunset crawling on limestone rocks at 130 meters elevation up a steep hill.

Food: Primarily rats and other small mammals. Probably frogs, lizards, and possibly other snakes. Probably they are quite opportunistic and eat whatever presents itself.

Defensive Behavior: These snakes are quite adept at defending themselves. They have almost endless energy and don’t seem to stop after 10-20 strikes as most snakes do, they can continue more than 60 times.

Venom Toxicity: These are rat snakes, they have venom in their saliva, but it does not act on humans to cause serious envenomation. Ptyas carinatus venom is rich in neurotoxic 3FTx and affects animals they eat, but not humans.

Offspring: 

Notes: I have seen about two dozen of these snakes, about 20 of them in the wild – usually forest. They are very fast on the ground, and I have never seen them climb trees, but I have seen them easily climb the sides of large limestone cliffs, poking their heads into holes to see what they might find to eat. These snakes are sometimes mistaken for the king cobra (Ophiophagus hannah) as they are about the same size, general shape, and they even have some striping that can be mistaken for the king cobras. These snakes are active throughout the daylight hours and are best caught by tailing them while they are going through brush so they cannot twist around and strike. These snakes are one of the few species in Thailand that can hiss when aggravated. Today on the trail up a mountain in Tub Kaak in Krabi, I caught a 1.5m specimen and he hissed repeatedly as I tailed him and he tried to twist through the small bushes to get away. Other snakes that make noises with their mouths are: Burmese pythons, King cobras, Monocled cobras, spitting cobras of both types (equatorial and siamese), and the Russell’s viper (Chain viper).

This rat snake gets to be nearly 4 meters long. The images here are of an almost 3 meter specimen from southern Thailand. Keeled rat snakes have a big bite and a big reach when striking, so be careful!  The teeth and jaws on this large rat snake are very strong and they can leave wicked scars.

Ptyas carinatus

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Genus: Ptyas
Species: carinatus or carinata
Binomial name: Ptyas carinatus, P. carinata

Günther, 1858

Ptyas carinatus - Keeled Rat Snake, a non-venomous snake in Thailand.

Video of a small Ptyas carinata I caught crawling among limestone cliffs in Krabi province, Thailand:

Ptyas Carinatus – Keeled Rat Snake

Ptyas carinatus - Keeled Rat Snake, a non-venomous snake in Thailand.

These are great snakes. They get big. This one is 2.75m. This is another one that hasn’t calmed down since being caught. They are rat snakes, so that’s what they prefer. Unfortunately we don’t see many rats around this area so I couldn’t catch one to feed it to him if I wanted to. If I find a pet store I’ll buy a couple rats and see if he’s hungry. Unfortunately these snakes die quickly after being caught – so it will probably become dinner for one of the big king cobras – if they’ll eat it.

There are some color variations in these snakes. Here’s a Ptyas carinatus I caught that was much more green.

Ptyas carinata – carinatus – Keeled Rat Snake

I found a lovely specimen of the Ptyas carinata snake on the way down a mountain this evening. It was about 6:45 pm and the sun had set 15 minutes before. I was running down the steps and took a few seconds to breathe – when I saw the snake on some limestone rocks beside me. It was dark, so it was hard to say – was it a king cobra? Kings are good climbers too. Was it a rat snake? I just couldn’t tell for a while. I looked at the tail multiple times (I was grabbing it by that point and trying not to get bitten by the snapping jaws).

The tails of a couple kinds of rat snake look JUST like the king cobra tails.

Eventually I realized it was a rat snake and quickly pulled my shirt off to attempt to locate his head in the pile of branches he was trying to twist though and get lost in.

I grabbed too low once and he twisted around and bit. The shirt was wrapped two times around my hand – so, no damage. It is very hard grabbing a 1.5 meter snake in the dark when you can’t see his head. No flashlight… nothing. Exciting – yes. If it was any bigger – it could have been REALLY exciting because I would have been bitten a couple of times I think.

Ptyas carinata are fast snakes and strong biters. They eat rats for god’s sakes… rats are tough little beasts.

I’ll have a full write up of the snake tomorrow, photos and videos. My good camera is with my wife who is traveling. I’ll have to make do with the iPhone camera. I’ll try to find some good light to shoot photos and video in tomorrow so the media doesn’t totally suck.

Here is the Ptyas carinata video I took of this snake: