Animals can an forge interspecific bonds when the desire for social interaction pre-empts their normal biological imperatives. The manatee is what it seems, a very passive non-agressive mammal whose actions could be as simple as enjoying companionship. Then it may be a passive defensive tactic to protect it's mate or young. The swamp lizard, while more advanced than most herps, still has a reptilian brain relying more on instinctive behaviors not involving higher brain function. Animal agregations are often related to evolutionary advantages of defensive or cooperative foraging as school of fish, flock of birds, herd of herbivores, pack of wolves, pride of lion or team of athletes.