Emphasis on bright. The insect’s dull brown wing casings flew apart to reveal vivid bands of red, black, and electric blue. The inconspicuous leaf suddenly transformed into a garish Christmas bauble.

Many animals do something similar. When a threat gets close, they flash bright colours, show off distracting eyespots, strike aggressive poses, and spray off-putting chemicals. They hiss, rattle, puff, and arch. These spectacles are called deimatic displays and they are supposedly meant to distract or intimate predators. Bright colours, in particular, are often messages that scream: “I AM TOXIC; DO NOT EAT ME.” For some animals, these claims are bluffs. For the mountain katydid, they are genuine warnings—this insect is full of foul-tasting chemicals.

But Umbers noticed something unusual about