Attacked by misinformation, virulent on the Internet, I have turned to the

dictionary and been amazed at the gems there, hiding in plain sight, and at

the quiet eloquence of the tome.

The American Heritage Dictionary, 4th Ed. spends half a page on the word "head,"

and two nounal meanings stand out.

    8. (Used with a single verb) The side of a coin having the principal design,

    often of the head of a famous person, and the date. Often used in the plural

    with a singular verb.

    10b. pl. head A single animal: 20 head of cattle.

An example for the 8th sense would be: "When flipping a coin, heads comes up X

times in a row."

Both in the wild would have looked weird to me: a plural noun followed by a

singular verb and "head" as a plural noun. Sure I had seen the two before

meeting them on page 807 of the dictionary. How did I let them pass? Well, this

time it was different and I paid attention.

10b may be easier to remember with 10a

    10a. An idividual; a person: charged five dollars a head.

That is, head is a singular noun when referring to a person and yet can be a

plural when applied to animals. Equality, like a virus, stops at species

barriers.