Invasive Species
Non-native species can outcompete and harm local wildlife.
About this topic
Invasive species are non-native organisms that spread aggressively and harm ecosystems, economies or health. Without natural predators or diseases, they outcompete native species for resources, prey on them or bring disease. Examples: cane toads in Australia, grey squirrels in Britain and zebra mussels in North America.
Species are introduced by accident, such as in ship ballast water, or deliberately, for pets, farming or pest control. Not all non-native species become invasive; most fail to establish. Those that do often reproduce fast, tolerate many conditions and eat many foods. Island species are especially vulnerable because they evolved without such threats.
Cane toads were released in 1935 to control beetles on sugar cane but did not eat them, spread widely and poisoned native predators that tried to eat them. Grey squirrels carry a virus that kills red squirrels. Japanese knotweed damages buildings and crowds out native plants.
Control methods include removal, barriers, biological control and prevention, such as checking ships and luggage. Biological control can backfire, as the cane toad shows. Students often think invasive means harmful by nature; it is the new environment that creates the problem. Remember that invasive species are a leading cause of extinction.
Key ideas
- No natural predators
- Cane toads and zebra mussels
- Prevention is cheaper than control
Quick check
Use cases: where Invasive Species helps
- Homework: review the key idea behind Invasive Species before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Invasive Species without notes.
- Visual learning: play with the interactive lab to see how Invasive Species changes when you adjust its inputs.
- Teaching a friend: explain Invasive Species in your own words, then compare your version with the key ideas.
Biology underpins medicine, farming, conservation and biotechnology.
Frequently asked questions
What is Invasive Species?
Non-native species can outcompete and harm local wildlife.
What will I learn in Invasive Species?
No natural predators. Cane toads and zebra mussels. Prevention is cheaper than control.
Is Invasive Species part of Biology?
Yes. It is one of 150 Biology topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Invasive Species lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Invasive Species?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.