You gotta be able to feed your PETI, right?

There are functionally two classes of food: it's possible that depending on game balance and available resources, multiple foods of each type will be defined:

• FOOD, being the principal source of health. This type of food affects only the upper nibble of HUNGER_FUN, i.e. only raises the hunger score, but it also has no deleterious effects.
• SNACKS, which optionally raise either just fun, or hunger and fun concurrently. In doing so, it will also affect the "weight" bits of the Health_Byte. Higher weight may be referenced along with the rest of the health byte during evolution as well as being a key part of weighting the otherwise random decision on each device update to make the pet sick or not.

Hunger is depleted in an incremented and predictable fashion each time the system 'ticks' through an update, based on the rate defined in the current stage. Additionally, at certain transitions along the hunger bar, the pet will soil itself up to 4 times total, also affecting the health rate. Being soiled is a multiplier on the depletion of fun.

A pet whose fun or hunger meter has depleted entirely should alert.