A freeloader that can spread only when its host reproduces ought not to be overly harmful: too much damage to its unwilling benefactor will affect the parasite's own chances to procreate.
A freeloader that can spread only when its host reproduces ought not to be overly harmful: too much damage to its unwilling benefactor will affect the parasite's own chances to procreate.
吃白食的若只能随宿主的繁殖而散播，就不该明目张胆地使坏：要是寄生虫将不情愿的施主伤得太重，自己的繁殖机会也跟著遭殃。