Prediction: If snakes are experimentally excluded, then the population of rabbits will increase, or at least will be greater than that where snake predation happens. Design: Exclusion fences. Problem: Hawks perch on fences using them as a vantage point from which to predate on the rabbits. Procedural control: Cage with roof only (no fence) Fence with holes( Cage with roof only (no fence), Fence with holes )