Meet sibling sleuths Nicki and Ricky -

and the mysterious birds in their neighborhood - as they embark on scientific explorations to solve natural mysteries.

This volume collects the first three books in the Adventures of Nicki and Ricky series:

THE MYSTERY OF THE SHELL TREE

THE HUMMINGBIRD CONUNDRUM

and THE CASE OF THE DUCK'S TEETH

in a special hardcover edition.