Are nonhuman beings conscious? How does one define what it is to be conscious? Does the absence of an elaborate language, which is often considered evidence of conscious thought, as also a window through which we conventionally understand consciousness, indicate that other-than humans have never evolved into conscious beings? Bonnet monkeys, with whom I have spent more than two decades of my life, appear to be knowledgeable about one another's behaviour to different extents. But do they know as much about each other's beliefs and intentions? Are they adept at recognising the similarities and differences between their own and others' states of mind? Attribution of mental states to other individuals could manifest itself in diverse situations as, for example when individual animals closely observe the actions of others, when they interact competitively or when they deceive one another in the social sphere. This talk will examine some of the theoretical and philosophical issues underlying our understanding of nonhuman cognition, with a particular focus on social knowledge and tactical deception, processes integral to the cognitive biology of wild bonnet macaques, a primate species found commonly in peninsular India.