Invasive species are harmful not because of what they are, but because of

What they do

Explanation: People put goldfish in lakes and creeks and ponds they invade the area and eat everything there and the animals that are there they take all the recorses that the other speices need

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.

i'll try what topic lol