Deterrence principle
Lessons from Cane Toad
Be costly to attack.
Poison-Gland Defense

Core lesson
Some boundaries work because crossing them has a real cost.
Biological basis
Cane Toads have large parotoid glands that secrete potent toxins. This chemical defense deters many predators and helps the toad survive despite being slow-moving.
Best use cases
Where this lesson tends to be most useful in practice.
Self-protectionEnergetic boundariesDeterrenceHostile environmentsRefusal