Why sheep cross the road in front of vehicles

Sheep behave in ways that seem suicidal to some people. But when sheep cross the road in front of cars and trucks it is because they are following their survival instincts. Sheep evolved long before humans and their instincts haven't changed a lot since. Instinct mostly guides their behavior.

Sheep and other animals are unlikely to evolve in response to motor vehicles because humans have taken control of their breeding. For them to evolve more appropriate responses to cars and trucks, their breeding would need to be determined by their response to events and situations.

Go to the home page: OrganicExchange.com.au for more grazing & farming info you can walk out & use
Site conditions
No body represents this as:
free from omissions
free from errors
suitable for your use
nor as advice.
Your situation is different from anyone else's. Make informed decisions and if necessary get advice
Keeping them behind fences and controlling their grazing prevents this. As does our direct management of their breeding by choosing which animals mate with which other animals.

Mammals such as sheep follow many principles that we humans have found useful and sheep have found essential. These principles protect them from wolves and other predators that we don't have to worry about.

We have used these principles for thousands of years, sheep have depended on them for millions of years. So the principles were in place in sheep behaviors long before humans evolved and way before the motor car arrived. Some of those principles are
Follow the leader
The oddest-seeming example of this is sheep jumping over a barrier. If you remove the barrier, the following sheep often just keep jumping where it was. They follow the example of the sheep in front simply because they don't discuss it. Therefore they don't know why the others were jumping, nor why it has become no longer necessary. They follow the sheep in front because it saves time, saves accidents and because it worked for the sheep in front. If each sheep stopped, examined the situation and made a decision, the mob would be slowed and the tail-enders might be eaten. And some of the decisions might be bad ones, the sheep making the decision on less than sufficient information or understanding might fall down a ravine and die.

There's safety in numbers
Therefore it is better to congregate in big mobs to ensure that most survive any threat. A wolf or even a pack of wolves can only eat so many sheep, the rest will escape and survive. Plus, the mob can protect the younger ones by keeping them in the middle and arranging the stronger ones to the outside in defense.

The survival of the group sometimes depends on individual sacrifice
This is seen where a person gives their life to save the family or a parent loses their life in keeping their child alive. In sheep, many a ram dies keeping predators at bay. Many a ewe is lost giving birth to a lamb or protecting one from a predator.

Head for the hills
Many things support this:

Survival of the fittest
The boys slug it out, head to head to see who has the best skill and skull for pushing wolves off cliffs. Any with weak skulls, unbalanced horns, poor ability to survive rough play etc are ranked lower.

The tough guy gets the girl(s)
Hollywood has made a fortune out of this one and many an otherwise sensible adult human has followed it. It works well for sheep, even if it is not necessarily ideal for humans. The ewes mate with the leading ram in preference to younger or weaker ones. This ensures a high concentration of the genes for leadership and mob survival:

Age before beauty
They respect their elders, some of whom may be far from attractive, particularly if they have spent much of their lives bashing their heads together.

There are lots of things in our technically advanced world that sheep are not adapted for. Sheep respond to the confusing arrival of a vehicle by reverting to these basic survival principles. As a result they follow the leader in the mob and if that leader happens to cross the road, perhaps to Head for the hills, they follow. After all, There's safety in numbers.

Sometimes a sheep that is not the leader crosses the road. If other sheep spot this animal crossing and don't realize it is not the leader, they may be drawn more by its movement than by the stillness of the rest of the mob. Because sheep are vegetarians and are eaten by other animals they have eyes on the side of the head. Their vision is tuned to moving objects such as predators more than to still objects such as trees. Therefore they notice this new leader and follow it to stick to their principles. As a result of sticking to what they know best, they happen to cross in front of a vehicle and the driver brakes or has a woolly landing.

Once people are aware of how sheep are likely to behave, they are better able to predict it and save themselves some sudden stops. They also come to respect the principles more, particularly when they see humans showing the same instincts.

To test it, stand on a busy city street corner and watch the pedestrians. Even though the traffic lights don't say "WALK", some pedestrians who have waited a while for the green may follow a false leader who steps out when they think it is safe, though not legal to cross.

I've seen many a city person look decidedly sheepish after a bus skidded to a halt to avoid ramming them and bringing to an early end the woolly thinking and the behavior that followed it.

If you would like to contact us, please use this link.

If you are looking at a printed version of this page and you would like to visit it on the internet and get a stack of other info that may assist you, the full web address is

All material on this website is copyright 2007 Michael Burlace, The Organic Exchange Pty Ltd and others as shown. Material on this website may be downloaded and printed for your personal use only.

FarmRef and Organic Exchange are registered trademarks and Info you can walk out & use is a trademark of Michael Burlace.

This page was updated on December 27, 2007