Just because there's a 99% chance the bush has no predators behind it does not make it rational to assume there are no predators. In Bayesian decision theory,

Just because there's a 99% chance the bush has no predators behind it does not make it rational to assume there are no predators. In Bayesian decision theory, you'd choose the action (walk directly by the bush; walk by the bush but have your guard up; steer clear of the bush) that minimizes your loss function (e.g. probability of dying or probability of your blood line dying out). You'd end up picking a path that balances the risk of being eaten by a lion with the cost of having to walk further (and thus having less time and energy to gather food; or tripping and cutting yourself and dying of infection; or whatever).