When many individual organisms,like locusts,bacteria,anchovies,or bats,come together and move as one coordinated entity,that's a swarm.From a handful of birds to billions of insects,swarms can be almost any size.But what they have in common is that there's no leader.Members of the swarm interact only with their nearest neighbors or through indirect cues.Each individual follows simple rules:Travel in the same direction as those around you,stay close,and avoid collisions.There are many benefits to traveling in a group like this.Small prey may fool predators by assembling into a swarm that looks like a much bigger organism.And congregating in a large group reduces the chance that any single individual will be captured.Moving in the same direction as your neighbors saves energy by sharing the effort of fighting wind or water resistance.It may even be easier to find a mate in a swarm.