The main difference between male and female toads of many species is size, with males tending to be noticeably smaller. The adult female common or European toad, for example, can reach up to 13 cm, snout to vent (or anus), whereas the male counterparts are usually around 8 cm.
Male European toads can also be distinguished from females because they have nuptial pads, or spiked growths that aid with grip during breeding, on their first fingers outside of breeding season and on their first, second and third fingers during the breeding season.
Another key difference is color; male common toads have a uniform light greenish-brown or grey color, while females are darker brown with spots or bands. The male American toad has a darker throat or dewlap, which he expands to make a shrill and distinctive mating call in the spring, which is often likened to the sound of crickets.