Life Cycles

Adult salmon spawn at the end of their life cycle. They fight strong currents while swimming upriver to the place where they hatched. Young readers will follow a salmon from egg to adult.

The life cycle of a frog takes place in water and on land. It begins in spring with a male frog croaking a song to attract a female. Young readers will read about and watch an egg develop into a tadpole and then into an adult frog.

A female butterfly lays eggs on a leaf to begin the butterfly life cycle. The eggs hatch into caterpillars, and caterpillars form chrysalises to change into butterflies. Students will follow a butterfly as it grows from an egg into an adult.

Penguins must complete their life cycle in very cold temperatures. To protect their eggs from the cold, penguins use brood patches. Students will watch a penguin chick hatch from an egg and grow into an adult.

Dogs begin their life cycle as puppies in a litter. A newborn puppy sleeps for 20 hours a day as it grows! Children will watch a puppy move from a large litter to a loving home as it grows up.

Bees begin their life cycle as eggs in honeycomb cells. Every day, a queen bee can lay as many as 2,000 eggs. Young readers will study a bee's growth from egg to grub to pupa to adult.

One cold, rainy, spring night, a young girl and her scientist father participate in "Salamander Night" to follow hundreds of spotted salamanders as they venture into a vernal pool to mate and lay eggs. Together, the father-child team studies the salamanders through their complete amphibian metamorphosis, culminating in the adult salamanders' disappearance into the woods in late summer. In easy-to-understand text, the girl relates the tale through her illustrated, photographic journal.

Ladybugs spend part of their life cycle as larva. Every day a ladybug larva eats about 30 tiny green insects called aphids. Young children will watch a ladybug go from egg to adult.