Yet, I almost never post about science. Maybe that should change.
The following is a fascinating video, part of the evidence provided in support of the claims contained in an also fascinating 2009 paper by Sanz, Call and Morgan:
I don't suppose I need to comment how powerfully evocative the video is, in a general sense.
But beyond that general effect, to me it is suggestive for at least two additional reasons; one of which can be gleaned here (perhaps to the surprise of most):
"Equal quantities of labour, at all times and places, may be said to be of equal value to the labourer. In his ordinary state of health, strength, and spirits; in the ordinary degree of his skill and dexterity, he must always lay down the same portion of his ease, his liberty, and his happiness. The price which he pays must always be the same, whatever may be the quantity of goods which he receives in return for it. Of these, indeed, it may sometimes purchase a greater and sometimes a smaller quantity; but it is their value which varies, not that of the labour which purchases them. At all times and places, that is dear which it is difficult to come at, or which it costs much labour to acquire; and that cheap which is to be had easily, or with very little labour. Labour alone, therefore, never varying in its own value, is alone the ultimate and real standard by which the value of all commodities can at all times and places be estimated and compared. It is their real price; money is their nominal price only." (A. Smith. The Wealth of Nations, Book I, Chapter V. My emphasis)Any comments?
 Crickette Sanz, Josep Call and David Morgan. 2009. Design complexity in termite-fishing tools of chimpanzees (Pan troglodytes). Biol. Lett. published online 4 March 2009. here