@Atlantis74 pointed out that at some point there were 51 chickens on her housing block! Although hilarious (in my eyes), this can also be extremely annoying, so we've had a chat on possible ways to control this sort of problem in the animal kinship group, and this is a paraphrased compilation of what we've come up with so far (please correct me if I'm misrepresenting you):
@Atlantis74 and @roderick ordonez: set a limit on housing blocks and/or other locations for each type of animal (maybe to something like 10).
@Zaphod: Allow the devs to continue to monitor and control animal population, or allow players to poison animals like they can trees (with some immediate reservations as to the ethics of that suggestion).
@shepherdmoon: Allow butterflies and chickens to be captured by players in addition to piggies, so they can be removed from overpopulated areas by players. If the sole method of controlling the population is by player removal of animals, then the hard limit of one piggy hog-tie per area should be lifted. Otherwise, there may also be a "natural selection" element to the game where, when the population of an animal type exceeds the location's ability to support all of its members, then the animals' numbers naturally and slowly dwindle down until they reach equilibrium with their environment. I would also like to add that it would be a cool effect for any "disappearing" animal to explode into a pile of meat, milk, or grain (unless milk is considered too precious, in which case butterflies could just go "poof"!)
@Rascalmom: Added that "netting butterflies" could be used not only to capture them, but also make massaging and milking them easier (for hard to reach ones). Perhaps chickens could be "chicken-tied". Also liked the idea of dwindling numbers for overpopulated animals.
@Phoebe Springback: Add the ability to donate excess chickens (etc.) to the giants, of course with some sort of snarky reply from them...