Hence opinions differ internationally as to whether it is worth trying to "eradicate" alien species. All the more so since many introduced species spread like wildfire and reappear at the drop of a hat, so that the enormous cost and difficulty of eradication programs often causes them to be abandoned before they are complete.
因此是否硬要「驅逐」外來種，國際上也有不同意見，何況外來種往往野火燒不盡，春風吹又生，高昂的代價常讓剷除動作無疾而終。