David, I'm really at a loss of words here. You take care of ten snakes and one frog. From the sound of it, your friends and family just gives you the snakes and probably even the materials and money so you can buy food and other things for the current pet you are taking care of. I think, instead of just taking the snake from your grandpa, you should purchase it from him, and buy your own supplies and everything for your snake.
When I finally convinced my parents to allow me to have a pet snake, I had to do all the research, buy all the materials, the food and all the random stuff that I would need for my corn snake. My step-mom used to own two boas (not the same, I know) but the information and knowledge she knew really helped me along. I found this site as well, and thats what really helped me of care for my corn snake. I am very proud of myself for doing the research myself and buying everything for my snake. I started out with a ten gallon, and in total with all the supplies it cost me at least 160 dollars. (including the snake). I now have her in a nice big 30 gallon (long) and she is in paradise. The tank is literally covered with things I bought myself, and i'm fairly impressed on how it looks so far.
To me, it sounds like your parents buy all your snakes and materials, and I think that really doesnt help you be responsible. I say pick up a job and earn your money and buy the snake from your grandpa, or do some work for him at his house. Earn your snake, I can understand if its a gift or something, but please consider making it up to him.
I really do hope you read all this, and I hope you'll wont just disagree and argue of what i've said, I took atleast five minutes spilling my heart over this.
-John