I am not aware of anything your snake could catch.

The numbers seen like 1.2.3 means this.
The position number one is in dictates male.
The position number two is in dictates female.
The position number three is in dictates unsexed.
Then the number itself tells you how many of that sex and species the keepers has. So 2.3.1 Ball Pythons tells you the keeper had 2 males, 3 females, and 1 unsexed.

As for the weight. That just gives a better idea of the snakes size as age does not. Plus I think many snakes actual age is unknown by the owner. Weight is usually more important, especially to breeders.