# How many people go into a Kaiju and how much urine comes out?

Over at my not so famous blog, Deep-Sea News, I discuss allometry of body size and how we can use it to predict some features of fictional sea monsters (Part 1 and Part 2).

For background, biologists know that much of an animal’s biology, everything from limb length, heart volume, lung capacity, territorial range, and urine production, all scale with body size. We use an equation, based on data from lots of animals, to calculate all of these. The equation usually takes the form of Variable of interest = a (mass)^b. athe intercept usually varies among groups like birds, mammals, frogs, carnivores, nocturnal, carnivores, etc.. b the slope can as well but usually scales as a multiple of 0.25. By knowing the mass of an animal, we can gain some insights even in the absence of direct observation, like how many people a day a Kaiju would consume.

if Kaiju are essentially mammals, complete rubbish at digestion, and assuming long tons, then the largest Kaiju, Slattern at 6,750 tons, would require 314.2 people per day. In 61.7 years it could eat its way through Hong Kong, assuming of course there were no births and no other non-Kaiju related deaths. Who has time for sex when they’re running from a 6750 ton alien?

Piss…how much would it produce? Every day a Kaiju, if mammalian, would produce about 40 barrels worth of urine. If Kaiju are like frogs, then Slattern would produce 92 Olympic swimming pools worth of urine per day (roughly 0.8% of flow rate of the River Thames).