In the category of other critters one of my favorites is crows. They communicate endlessly while doing things that I do not understand. Part of the problem is that their group behavior is spread over a large area and often hidden in the trees, but even when I can see what they are doing I often do not know what it is. Yet they put a lot of effort into doing it and a lot of communication is involved, so it must be useful. We just do not understand it.
In particular crows know how to count, or rather they have calls that require counting in the sense that a specific number of sounds is repeated. We think of counting as a mental verbal exercise but it need not be. I can decide to take three steps then take them without verbally counting them in my mind. I can also see that there are three horses in the field without mentally verbally counting them.
One of the great obstacles to understanding animals is that we confuse our mentally verbal thinking with thinking in general.
Crows have many different calls, some of which clearly require counting. My favorite call involves two kinds of counting. It is a five caw call that goes caw caw-caw caw-caw. Like Morse code there are timing based pairs within the overall count of five.
But there is also a simple three caw call that is frequently used, and several others, possibly many others. I have never tried to count the calls and I am not sure that I could, because I may not be able to tell them apart.
Note too that what a call means may depend on the situation, or the context as it is called, just as with human communication.
I assume the crows know how and when to make these calls by instinct and they also know what they mean by instinct. But they still have to count when they do it.
Horses do not verbalized constantly the way crows do, but they make extensive use of gesture and posture to communicate. But this is another topic, for another posting.