“There are indeed two different kinds of upward-walking mammals, much like your own species, but much larger, and with infinitely keener senses. They are indeed amazingly swift creatures, and through scent alone they are aware of the presence of man when any member of your species is at all in the immediate area — standing, say, at least several miles away. Vegetable matter is a main diet, though often supplemented by insects, which are considered a delicacy.
[… 1 paragraph …]
These creatures do indeed remember, but their remembering operates extremely rapidly — a kind of almost instantaneous deduction that comes as sense data is interpreted. That is, received and interpreted almost at once, or simultaneously.
Offspring do not occur until the individuals are well past the age that you would consider normal for breeding. Otherwise the procedure is the same. With some territorial variation, such creatures reside in many of the world areas on your planet, though their overall population is very small — altogether, perhaps, several thousand. They rarely congregate in large groups, but do have a family and tribal-like organization, with at the very most twelve adults in any given area. As offspring are added, the groups break up again, for they know well that in larger numbers they would be much more easy to discover.
[… 2 paragraphs …]
They have a keen understanding of nature, and of natural phenomena. Language is not developed to any great degree, for their sensual ordinary equipment is so pure and swift that it almost becomes a language of its own, and does not need any elaboration. Those senses possess their own variances, so that without any word such as “now” or “then,” the creatures are able to know quite accurately how many living creatures are in the vicinity, how long they have been there (pause) — and their experience with time is one that follows the seasons in such a way that they have formed a wordless, fairly accurate picture of the world, including navigational direction.”
WTH Chapter 1: January 10, 1984