THE HAGUE, South Holland :Zoologists are baffled by the strange behaviour of a troop of baboons at a Dutch zoo which have become inexplicably withdrawn, apparently fearful of an unseen threat. “They became panicked at the end of the day on Monday, they were hysterical, not jumping around but behaving strangely,” zoologist Wijbren Landman of Emmen Dierenpark in the northern Netherlands told AFP on Friday.