These interactive task cards will go perfectly with your intermediate "Animal Adaptations" and "Ecosystems" units. (For an example of what you will get with these interactive task cards, check out the Thanksgiving Interactive Task Cards Freebie
in my store.)
8 Interactive websites, articles, videos, etc. that can be used is so many different ways. Use them at the computer workstation and allow your students to work through each activity independently. Use them for homework and/or extra credit. Use them as a teaching resource. Some activities are going to be more challenging and take longer than others. They are all a great review of animals and ecosystems.
Other intermediate products in my store:
Holiday Multiplication and Division Review
Grades 3-5 Technology I Can Statements