Ultimately, the answer comes down to breeding. No, not thát kind of breeding! I mean the kind that results in
Making More Biscuits!
You see, the entire life span of any biscuit species is long and complex and, oddly enough, requires a trip through one of a small number of domesticated species' digestive tracts. Mostly humans, but also dogs and cats, in the case of a smaller number of biscuit species.
You see, any kind of biscuit begins life as a seed called "corn", and there are several variants that can ultimately become biscuits, the most populous kind being "wheat". After the seed matures, it enters a sort of larval stage called "flour" where all the corns amalgamate into a kind of mega colony where they await further development. The flour stage can last from several weeks to several months or even years.
But once activated, by the consumption of certain sugars & fats, the larval flour moistens, thickens and matures into its pupal stage called "dough", and it is from the dough that individual biscuits mature in a very hot envronment.
After this intense period of maturation, the adult biscuits emerge, and after a time of intense courtship, make use of their curiously evolved mimicry (the ability to "talk" and make "music" in the fashion of humans) which endears the humans to them to such an extent that they can hardly put the packet of biscuits down before gobbling the whole sweet lot!
This is actually precisely what the adult biscuits' goal is, to be eaten by humans! Because it's the humans whose wastes (their own as well as their animals') that will fertilise the next generation! Biscuits have apparently achieved this curious symbiosis after millennia of careful breeding of a species capable of engaging in agriculture. It's further thought that the very brains of the humans have in some curious way been modified such that they have become willing & complicit partners in the suicidal reproductive cycle of the biscuit.
As a matter of clarification: it has been brought to the Commission's attention that human farmers do not (or rather rarely) use human excrement to fertilise their crops. Biscuits are well aware of this, as a matter of fact. If they specialised in passing through the intestines of cows and sheep and so forth, biscuits wouldn't get very far on account of cows and pigs can't cook. What they've come to depend on is a creature just bright enough to engage in agriculture, but yet just dim enough to not question the eating of a sentient species.