Army ant chimpanzee toolkits

A nice story about Crickette Sanz' and David Morgan's work with chimpanzees of the Goualango Triangle, and the tools they use to forage for army ants:

Unlike other instances of chimp foraging of ants, these apes regularly used more than one implement to root out the insects. On average, tools were found in sets of three or four, although chimps assembled as many as 18 together.