From site:  The Pavlov’s Dog game and related reading are based on some of the scientific achievements of Ivan Pavlov, who was awarded the 1904 Nobel Prize in Physiology or Medicine. Even though the first image that comes to mind with Ivan Pavlov is his drooling dogs, he was awarded the Nobel Prize for his pioneering studies of how the digestive system works.  

• – What’s a conditioned reflex?
• – What’s a stimulus?
• – How can you learn a conditioned reflex?

In this game, you will find out if you can train a dog to drool on command – an example of a conditioned reflex. Ivan Pavlov’s description of how animals (and humans) can be trained to respond in a certain way to a particular stimulus, paved the way for a new and objective method of studying animal and human behaviour.

The object of the game is to train Pavlov’s dog to respond to a signal that it will associate with being fed. Choose the right signals with his food and you will successful; choose the wrong options and the dog will refuse to respond to your signals.

Note that this game uses Flash.  You will need a Flash emulator extension on your browser, such as Ruffle, to play it.

From site: 

Teachers, students, and families across the country are exploring Monarchs, butterflies, and the mystery of migration! Join us as we investigate the world of the Monarch butterfly.

Life Preservers is a video game to help you learn about evolution, adaptation, and the history of life on earth.  You are a member of an ancient alien organization dedicated to protecting the natural ecosystem of planets where intelligent life might evolve.  Follow the timeline from dinosaurs and reptiles to mammals.

There are two game versions. The long version of the game includes the entire timeline and lasts about 45 minutes.  The shorter version includes only the Age of Dinosaurs and lasts about 30 minutes.

This is a Flash-based game.  You will need a Flash emulator extension on your browser, such as Ruffle, to play it.

From site:

Welcome to the wonderful world of extreme animals on Extreme Science, where you’ll find all kinds of world record animals, as well as some unimaginably creepy ones that dwell in the deepest depths of the ocean. Click on any of the record titles listed below and get all the fascinating facts about these extreme animals (and plants!) with cool animal pictures, too.

From site:  Animal Diversity Web (ADW) is an online database of animal natural history, distribution, classification, and conservation biology at the University of Michigan.