Invasive/ɪnˈveɪsɪv/ Definition 1 of 3Pro Tip 1/3Environmental Harm Focus on the damage invasive items cause to natural surroundings or established systems. Invasive insects can devastate local ecosystems. Pro Tip 2/3Rapid Spread Emphasizes the fast and uncontrolled growth or expansion typical of invaders. The invasive bamboo species spread rapidly, crowding the native plants. Pro Tip 3/3Human Action Often associated with species or practices introduced by people, not naturally occurring. Invasive species are often spread by human trade or travel.