How can you tell how old a rosy boa snake is?

To tell if the snake is a male or female, you can look at some external features or sex it. Usually the spurs near the vent are longer in males, and the tail is also longer in males. Also, you can use either the probing method or the popping method of sexing. With the probing, the snake should be about a year old in order for the measurement to be accurate, the probe will go in about 4 scales for females, and about 9 for male. For the popping method, you will have to squeeze the cloaca or the hemipenes out from the vent. If hemipenes appear, a small protrusion, then it is a boy, and if a whitish bulb appears, the cloaca, it is a girl.

Sources: I have multiple snakes, and multiple species.