Among the frogs, 100% rejected bombardier beetles and 75% rejected assassin bugs (Fig. 2), suggesting that the bombardier beetle is better defended against frogs than the assassin bug.

All of the pond frogs (n = 17) attacked and ate the male wasps. Although all of the tree frogs (n = 17) attacked the male wasps, 35.3% of the tree frogs rejected the male wasps (Fig. 2; see Video).

The coin is 27 millimeters across. Renato Gaiga A tiny frog endemic to the state of Bahia on Brazil’s Atlantic coast may have just earned the title of the smallest vertebrate in the world.