THE FIN, FUR AND FEATHER BUREAU OF INVESTIGATION 
http://www.fffbi.com

The Fin, Fur and Feather Bureau of Investigation (FFBI) is an international
website for students grades 4-5 chronicling the exploits of an unusual, animal-run
detective agency.

The site invites Field Agents to solve interactive mysteries on
two FFFBI missions:  Rainforest Undercover-an adventure to the Galapagos and the Amazon; and  Operation GAS-Chicken--a fowl genetic experiment threatens Mars.

The feedback from my own grade 5 students was overwhelmingly positive. The site uses uniquely written interactive stories and games to get kids to solve mysteries. 

As they’re doing this, students are learning language arts, math, science, and research skills to explore a wide range of subjects - from math and science to geography, genetics and history.

The teacher link describes in detail each interactive story and the time requirements for both. There are also monthly research challenges for elementary and middle school levels, missions to Japan, the Inner Pacific, Iceland, Brazil, South Africa, and Kenya, a multiple-round alibi game involving five suspects, multiple choice quizzes, a monthly newsletter filled with stories, puzzles, and thinking games. and a host of other intriguing activities. 

A great site which will keep your students reading, researching and exploring for hours.

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