I have long been enamored with security trade-offs in the natural world:

A 3D video tracking system revealed that although the bees became very accurate at detecting the camouflaged spiders -- they also became increasingly wary.

"When they come in to inspect flowers, they spend a little bit longer hovering in front of them when they know a camouflaged spider is present," said Dr Ings.

With this "trade-off", the bees may lose valuable foraging time -- but they reduce the risk of becoming the crab spider's next meal.

http://www.schneier.com/blog/archives/2008/09/bumblebees_maki.html