We currently have three flash card packs that I am using to teach my daughter about animals. We have Insects, Animals, and Sea Life packs, all found in the $1 section at Target. Here are some of the ways we use them.
We have a small collection of little animals that my daughter loves. For this game I pulled out all the cards that match her animals and set both the cards and animals out on her table. She immediately sat down and started matching them up without me saying a word. (We use these animals for lots of activities. They can be purchased at stores like Micheal's or here at Amazon.com)