The animal in a conflict between attacking a rival and fleeing may initially not have sufficient information to enable it to make a decision straight away. ① If the rival is likely to win the fight, then the optimal decision would be to give up immediately and not risk getting injured. ② But if the rival is weak and easily defeatable, then there could be considerable benefit in going ahead and obtaining the territory, females, food or whatever is at stake. ③ Animals under normal circumstances maintain a very constant body weight and they eat and drink enough for their needs at regular intervals. ④ By taking a little extra time to collect information about the opponent, the animal is more likely to reach a decision that maximizes its chances of winning than if it takes a decision without such information. ⑤ Many signals are now seen as having this information gathering or ‘assessment’ function, directly contributing to the mechanism of the decision-making process by supplying vital information about the likely outcomes of the various options.