Toads are amphibians, vertebrates that require both water and land to complete their life cycle. They differ from frogs by having drier, rougher skin, often covered in warts, and prominent poison-producing parotoid glands behind the eyes. Toads begin their lives as aquatic larvae called tadpoles, following a pattern common to nearly all amphibians. This process involves a transformation from a water-dwelling creature that breathes with gills to a land-dwelling animal that uses lungs.
The Aquatic Beginning: Egg and Larval Stages
A toad’s life begins in water, where the female lays her eggs. Unlike the gelatinous clumps of eggs laid by many frog species, toad eggs are typically released in long, double strings of clear, sticky jelly. This jelly layer swells upon contact with water, offering protection and buoyancy that keeps the eggs near the surface where the water is warmer and oxygen levels are higher.
Hatching occurs relatively quickly, often within three to twelve days, depending on the water temperature and the species. The newly emerged larvae are the tadpoles. Toad tadpoles are small, dark, and possess a round body with a powerful, laterally compressed tail used for propulsion.
At this stage, they are entirely aquatic, using external and then internal gills to extract dissolved oxygen from the water. Toad tadpoles are primarily herbivores, grazing on algae, detritus, and soft aquatic vegetation scraped from submerged surfaces. Their diet requires a long, spiral-shaped intestine to efficiently process plant matter. The tadpoles often live in schools, feeding and growing for a period that can range from one to three months before the next major stage begins.
The Transformation: Metamorphosis
The transition from a water-breathing, plant-eating tadpole to a land-dwelling, insect-eating toad is known as metamorphosis. This transformation is driven by hormonal changes and involves the sequential development of new organs and the absorption of old ones. The first visible sign of change is the emergence of the hind limbs, which begin as small buds and slowly grow into fully formed legs with five webbed toes.
The front limbs develop next, often appearing abruptly from beneath the skin fold covering the gills. As the limbs grow, the internal structure changes to support a terrestrial life. The gills are gradually absorbed, and functional lungs develop, forcing the transforming creature to surface frequently to gulp air.
The digestive system shortens significantly as the diet shifts from herbivory to carnivory. The most noticeable change is the reduction of the tail, which is absorbed by the body rather than simply falling off. Once the tail is fully absorbed, the transformation is complete, and the small, land-ready juvenile, sometimes called a toadlet, emerges.
Life as a Terrestrial Adult
Upon completing metamorphosis, the young toadlet leaves the water and begins its terrestrial life. Adult toads have a stout body, short legs suited for walking or short hops, and bumpy, dry skin. The skin contains numerous glands, including the parotoid glands behind the eyes, which secrete a toxic, milky substance called bufotoxin as a defense mechanism against predators.
Adult toads are insectivores, consuming a wide variety of invertebrates such as beetles, slugs, worms, and ants. They are largely nocturnal, emerging at night to hunt using their sticky, lightning-fast tongue to capture prey. During the day, they seek cover in moist, sheltered locations like burrows, under logs, or in leaf litter to prevent dehydration.
The adult stage culminates in the return to the water for reproduction, completing the life cycle. Males migrate to a breeding pond and use species-specific vocalizations to attract females. After mating, the female deposits her fertilized eggs, restarting the aquatic cycle.