how can you tell age?

i bought my snake from the pet store and have no idea as to how old hes his. can you tell age by length or anything like that? hes about 20-24" long now. he was about 18" long when we got him. we've had him about a month.

You can't tell for sure .... at the size your talking about, your snake is most likely a couple of months old.

-adam

thank you once again for the help, i wasn't sure if you could tell or not, thank you very much for all your help

Yeah like mentioned above, you can't tell. My male is a week younger than my female and has about 3'' on her.