A ball python is a type of constrictor snake that gets its name from its tendency to curl up in a ball with its head protected in the center when threatened. There aren't obvious difference between male and female ball python, but there are times when it's important to know the difference, such as when you're housing two snakes together and don't want babies in your future.
Lay your adult snake out straight, sliding him into a clear plastic tube if necessary. Cap the end of the tube to prevent escape, and make sure the diameter of the tube matches the snake's diameter. Measure the snake from the tip of the nose to the end of the tail. Females often grow to 4 1/2 feet long, although they can be as long as 6 feet. Males typically stay around 3 1/2 feet long.
Wrap a measuring tape around your snake's body to determine its circumference. Check it in three or four places to find the widest area. Divide the largest circumference by pi, or 3.14, to find the snake's diameter. Adult female snakes can have a diameter of up to 6 inches, while males tend to be smaller, staying closer to a 4-inch diameter.
Flip the snake over and look at the cloaca, or the opening near the base of the tail. Make sure his body is supported, either by laying him on a flat surface or letting him wrap securely around your body. Examine the small, curved spurs on either side of the cloaca. Male spurs tend to be longer than female spurs because they use them to hold the females during mating.
Take your snake to a vet so he can perform a cloacal probe or popping test. Both of these are more effective on immature snakes, although the probe often can work on adults. The vet will insert a small metal probe into the cloaca and measure how far he can safely insert it toward the tip of the tail. In male ball pythons, he can insert the probe farther than in females. For a popping test, he presses on either side of the cloaca to see whether male genitalia pops out.
- Don't attempt a cloacal probe or popping test on your ball python yourself. You can seriously injure the snake if you use too much force.