Here you have some resources to practice (and play!) with food chains:
1. https://www.cserc.org/sierra-fun/games/build-food-chain/
2. http://www.sheppardsoftware.com/content/animals/kidscorner/games/foodchaingame.htm
3. https://www.bbc.com/bitesize/articles/z93vdxs
4. https://www.bbc.com/bitesize/articles/zcgbjty
5. https://www.bbc.com/bitesize/articles/zsphrwx