According to cracked.com in this article: http://www.cracked.com/article_16762_6-biggest-assholes-in-animal-kingdom.html Cuckoo birds will gang up on any bird that won't take care of the cuckoos' eggs, but according to wikipedia: "birds whose nests are at high risk of cuckoo-contamination are known to mob cuckoos to drive them out of the area." It is the other way around. Did cracked make a mistake, or does it go both ways? Which birds are forming the mobs? Is it just the ones that cuckoos take advantage of, or is it both the cuckoos and the victims?