 If predators switch between host plants that provide toxins and plants that do not, depending on the abundance of larvae on each type, then automimicry of toxic larvae by non-toxic larvae may be maintained in a balanced polymorphism.A third hypothesis is that automimics are more likely to die or to be injured by a predator's attack.If predators carefully sample their prey and spit out any that taste bad before doing significant damage ("go-slow" behaviour), then honest signallers would have an advantage over automimics that cheat.