Weigh it's poop as well as the solids in it's urine. This should show you how much they are using for fuel/adding to their own weight.
Alternatively you can weigh them at one point and then 10 rats later weigh them again, and find the difference and divide by 10. That should show you how much they have gained. I would suggest doing it after they had pooped on both occasions.
why wouldnt you jus feed it one rat, then wait till it does its duty, then weight it. Id do it twice (at least, maybe 3 or 4 if its not clear) to see if its consistent, also weight the mouse first, of course.
E.R.P
}keepin it royal{
0.1 normal rp carmella
1.0 Lemon pastel rp Titan
0.1 crazy half airedale half pitbull Rubia
but thats assuming one rat = 1 poop? and snakes are diffrent more active ones will need more rats to gain the same amount of weight as the hide boxer
this is only my opinion dont flame me
Thanks for replying I don't know why I asked it I was just trying to see if I could guess around a certain time frame a snake should be a certain weight I know there certain things that could change it but if things stayed the same how much at a certain time so I was just wondering