When humans unknowingly interact with and alter the natural world, the consequences can be devastating. Find out how humans introduce plants and animals to ecosystems that aren’t prepared for them and what effects these invasive species have.
![Zebra mussel (Dreissena polymorpha) in pond](https://hmhfyi.com/6-12/wp-content/uploads/sites/4/2018/04/fyi_g10_c02_invasive_link.jpg)
When humans unknowingly interact with and alter the natural world, the consequences can be devastating. Find out how humans introduce plants and animals to ecosystems that aren’t prepared for them and what effects these invasive species have.