# Cattle Guards - how/why do they work? **URL:** \ **Category:** Factual Questions\ **Created:** [May 31, 2003, 12:42pm UTC](https://boards.straightdope.com/t/cattle-guards-how-why-do-they-work/178765 "2003-05-31T12:42:22Z")\ **Posts on this page:** 5\ **Page:** 3
**Author:** ![aceplace57](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aceplace57/32/3500_2.png) [@aceplace57](https://boards.straightdope.com/u/aceplace57)\ **Post date:** [October 23, 2012, 11:37pm UTC](https://boards.straightdope.com/t/cattle-guards-how-why-do-they-work/178765/41 "2012-10-23T23:37:29Z")
Our dogs wouldn’t walk across a cattle guard. I trained our Lab to jump over it. But she typically wouldn’t jump unless I had a treat in my hand. We had to get our cattle guard replaced. The heavy feed trucks had made it sink into the ground. It had to be pulled up and redone. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [October 24, 2012, 12:22am UTC](https://boards.straightdope.com/t/cattle-guards-how-why-do-they-work/178765/42 "2012-10-24T00:22:57Z")
> [@aceplace57](#): > > I trained our Lab to jump over it. But she typically wouldn’t jump unless I had a treat in my hand. So who trained whom? ---
**Author:** ![maggenpye](https://avatars.discourse-cdn.com/v4/letter/m/ecc23a/32.png) [@maggenpye](https://boards.straightdope.com/u/maggenpye)\ **Post date:** [October 24, 2012, 12:34am UTC](https://boards.straightdope.com/t/cattle-guards-how-why-do-they-work/178765/43 "2012-10-24T00:34:29Z")
> [@Machine\_Elf](#): > > Cow zombies. > > GRRRAAAAIINNNS! Best laugh of the day, thanks. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [October 24, 2012, 2:28am UTC](https://boards.straightdope.com/t/cattle-guards-how-why-do-they-work/178765/44 "2012-10-24T02:28:29Z")
I think it was Jerry Pournelle’s discussion on horse cavalry vs pikemen that mentioned horses will typically shy away rather than trample a writhing mass on the ground because they are very afraid of broken legs. Presumably cows, eveb zombie ones, are the same. Both cows and horses will run away from predators, or (for cows) circle to defend. A crippled cow or horse is a dead duck; it can’t run, it can’t keep up with the herd for protection. A crippled cougar or wolf can limp 3-legged and maybe feed off abandoned kills until the bone knits. A herbivore with a fracture is basically dead. This is (I have heard) why they shoot horses, don’t they. The horse has no instinct to get by without using their bad leg and will simply make it worse. I assume cows are the same way. So cows will avoid what appears to be uncertain ground. They will avoid gates that feel too uneven and potentially risky. The painted lines work because there is no such thing in nature generally - so cows have never needed the smarts or depth perception to figure out if a ground pattern is danger or decoration. In nature, 99% of the time, it’s danger. Horses, at least, can jump a 4-foot gap. Horses are head-up, watch for danger and run from it, jumping whatever gets in their way; cows are head-down, horns-forward defence or attack. They are not designed to jump because their defence method does not need them to. Darwin and other visitors mentioned the birds at the Galapagos. Originally, they were so unafraid that one episode, they landed on a sailor’s arm to drink from the pitcher while he was pouring a glass of water. A visitor about 2 decades later, when people had been there for a while, mentioned the boy sitting by the pond whacking birds for dinner needed a 3-foot stick because the birds would not come any closer. It seems there’s a “skittishness” gene, and it’s prominence comes and goes; a too skittish animal will not eat as well and lose out, a not skittish enough one becomes dinner. so the level of skittishness or wariness adjusts through selection… ---
**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\ **Post date:** [October 24, 2012, 3:37am UTC](https://boards.straightdope.com/t/cattle-guards-how-why-do-they-work/178765/45 "2012-10-24T03:37:33Z")
Zombie thread closed. **samclem** , moderator [Previous page](https://boards.straightdope.com/t/cattle-guards-how-why-do-they-work/178765.md?page=2)