When I have to many kittens I get out of catnip and my kittens die. So I was curious how much catnip a kitten requires?
Each kitten's base cost is 0.85 catnip per tick. Note that this cost can be reduced by Pastures, which reduce this number by 0.5% each and Unicorn Pastures which reduce this number by 0.15%. (Also, the Pasture reduction is subject to a diminishing returns effect when you push it past 75% reduction, so kittens' cost will never quite hit 0)
The relevant bit of the code, for those who are interested, is right near the top of village.js
catnipPerKitten: -0.85, /* amount of catnip per tick that kitten consumes */