The surface of Mars, photo courtesy of NASA (no herds of anything but boulders here)

Why do most non-predator animals travel in herds? At first glance you’d think it makes it way easier for a lion to snag a zebra if there’s 5000 of them going by, And it is, so why do zebras all travel together.  Why don’t zebras sneak around one or two at a time? 

The reason is the exact same reason people speeding on the highway travel in groups, flying by in the fast lane–it’s because although it’s still possible someone will get nabbed for speeding by those lions of the highways, the State Police, it’s less likely to be YOU. The point is that if there are six cars zipping along, and one cop car, only one person is going to get a ticket. Your odds, in a group, are considerably less than 100% that you personally will get a ticket, even though the odds of someone in that group getting a ticket are high. Traveling by yourself, not in a small herd, makes it very likely a ticket will be yours and yours alone. Same for a zebra–sure “a” zebra is going to be a meal for some predator, but if you are with 5000 other zebras, the odds are far less that it’ll be any one particular zebra, in particular, you (if you are a zebra). 

It’s not like zebras are calculating the odds, or even that they’re aware of it, but it’s evolution. Survival of the fittest. And in this case, meal type animals that herd are far more likely to survive, and thus pass on their herding ‘instinct’. This tells you something about animals–instincts govern behavior, and animals look out for #1, albeit maybe not consciously, just like people do. And, those instincts are inherited. Just how are instincts inherited? Probably through dreams, but more on that later. Hint–watch a sleeping dog run in its sleep. It’s probably chasing down a deer in a dream, which is just like you learning not to fall off a cliff or out of a tree by having 'falling dreams' when we are young.

Another way of thinking of why herding is beneficial is to consider the common phenomena of going to a place like Disneyland and meeting the person who bought your parent’s house, or that you’d met on a cruise, or that repairs your furnace. Most people think “WOW”....that’s incredible. And it is interesting and sort of surprising, but most people have a very large sphere of acquaintances, so it’s not that unusual to meet someone you know at some location where people like you gather. It’s amazing if you pre pick a particular person before leaving…if, without checking, you thought, “maybe I’ll meet my second cousins who live in Canada at Disney World”, and it happened. That would be amazing and you should play the lottery….but if you just met some random person you happen to know, it’s like winning $4 on a $2 lottery ticket. Or if you are a zebra, the lions got some other zebra, somewhere else in the herd, but they didn't get you.