Constrictor snakes are a very large family of snakes. They aren’t quite as large as in the number of them out there, but they can reach a much bigger size and weight!

The largest snake ever known to slither the earth is, unfortunately, the extinct Titan Boa. The Titan Boa could reach 42 feet long and weighed 2,500 pounds! This snake likely ate larger animals like alligators in its time.

Titanoboa skeleton

The longest snake kept in captivity is named Medusa. She is a reticulated python (Malayopython reticulatus) from Kansas city, and is 25 feet and 2 inches long! She can actually tell when it’s “show time” and she acts differently by posing for the camera! But Medusa isn’t the heaviest snake in the world. That goes to the green anaconda (Eunectes murinus), weighing over 550 pounds!

Reticulated python

So constrictors can get really big, but not all of them are. The Children’s Python only gets three feet long.

Constrictor snakes are divided up into two main categories, pythons and boas. These two are very difficult to tell apart in some cases, such as the green tree python and emerald tree boa. Both are bright green as adults, and bright red or yellow as babies (only the pythons are yellow as juveniles, the boas are only red or orange).

Both pythons and boas are considered “primitive” species because they have two lungs. These make them thicker bodied snakes, and, they still have tiny leg bones. Sometimes if you’re holding one you can feel what’s left of their toenails! They also have Pit organs just like the pit vipers.

In general, here are a few ways you can tell the difference:

  • Pythons lay eggs. Most boas give live birth.
  • Boas have fewer bones and teeth, whereas pythons have more.
  • Pythons usually have fewer and larger scales, while boas have more and smaller.
  • And lastly, pythons typically get to be a bigger size than boas. (Unless you’re in prehistoric times).

So, can you guess which one of these two snakes is a python and which is a boa? Use the arrow to move the picture back and forth!

*The snake on the left is the green tree boa, and the one on the right is the emerald tree boa. Another way to tell is that the green tree boa has an extra row of pit organs.