Mammalia

Sometimes, when out on a ninja mission, a fellow traveler queries my reason for not eating mammals.

My reasons are plentiful but I'll try to summarize them concisely here. But first, it would help to begin with an answer to the question, what is a mammal?

You might be surprised to hear (though maybe not all of you) that often, when presented with the information that I don't dig on mammals, people frequently counter with, "Oh, so you don't eat chicken?" Of course, my reply is always a puzzled look of wonderment, followed by a slow and careful, "Chickens... are... not... mammals..."

"Mammals (formally Mammalia) are a class of vertebrate animals whose females are characterized by the possession of mammary glands while both males and females are characterized by sweat glands, hair, three middle ear bones used in hearing, and a neocortex region in the brain."
- Wikipedia: Mammal

You may be surprised to find as well that live birth is not a requirement for the class of Mammal. The Platypus is a mammal. It happens to fall in a sub class called Monotreme (mammals that lay eggs), of which there are 4 other known species. But there are several things in the classification of mammal that I find non-appetizing, aside from the fact that I am myself a freaking mammal:

1. Being allergic to milk protein, whey, cheese, and any other derivative of mammary glad secretion, cultivation and marketing, I'm wary of all female mammals.
2. Sweat glands... nuff said.
3. Hair... as a theoretical compound, I'm not entirely against it, but in practice... ew.
4. A neocortex... (see below)

I don't care about the 3 middle ear bones, but the last number there, a neocortex, is very important:

It is involved in higher functions such as sensory perception, generation of motor commands, spatial reasoning, conscious thought and, in humans, language.
- Wikipedia: Neocort

Although the Wikipedia page specifically identifies 'in humans' for language, recent studies are showing that Dolphins, Prairie Dogs and several other animals have and use languages. I wouldn't feel right about eating anything intelligent enough to be able to tell me verbally to stop eating it. A chicken, lizzard or a fish may fight, but it won't look me in the eye and verbally communicate it's conscious desire to not be eaten.
For this reason, I also wouldn't eat a Parrot. I also refrain (for the most part) from eating Octopuses but that's just because they are not that tasty, fairly chewy, very intelligent and freaking bad-ass (YouTube).