On that note, there are some theories that magic mushrooms evolved to calm cows (or other grazing animals) down. Just like how people like to stare at complex geometric patterns cows may do the same. It's a theory called "fixation". Get a cow high and it is likely to stay in the same spot starting at psychedelic patterns for a bit. This may increase the chances for a cow to pick up and spread spores to a new location.
It's kind of a comical theory, but it makes a ton of sense. Also, I don't think it's been tested so take it with a grain of salt.