• Umbrellas - for some reason an umbrella can cause panic in a horse.  If you are walking near horses with one, do keep an eye on the rider to see if they are having a nervous fit as you approach.  If you are asked to take your umbrella down, do so slowly and do not flick the rain out of it.  Let the horse get well past before putting it up again.
• Raincoats, plastic bags or other things that rustle or flap in the wind.  Usually, this is just a case of ensuring that whatever it is, stops flapping.  If you are at the beach this can also include beach towels, surfboards and other human 'wierdness' (wierd from the horse's perspective). 
• Dogs.  While many horses are used to dogs, there are also many who either are not or have had a bad experience with a dog or puppy.  Keep dogs under control around horses, preferably on a lead if you are not sure how your dog will react to seeing a horse. Remember horses are prey and dogs are predators, even a friendly puppy will be viewed as a potential threat if it rushes at a horse. 
• Runners - while many horses will not bat an eye at a runner either coming up behind them or at them, it will often depend on how close you are to them and how calm or experienced they are.  From a horse's point of view, someone running is either running from something (that they might need to run from too) or running at them (to eat them).  In either case, this is something they tend to pay attention to.  Be particularly aware of your own clothing, a rustling raincoat at running speed is something that many horses are very wary of.
• Children - be particularly careful of small children around horses.  Although they may not intend to run them over or kick out, they have rather dodgy eyesight when it comes to objects around their legs and feet, a horse tripping over a child, moving a leg at the wrong moment or kicking an annoying object will easily do a lot of damage to a small child.  A horse's lower leg is all hard surfaces!

• The sheer size of a horse is frightening to many people. While you may see it in the movies, it is actually very unusual for a horse to run down a person.  If you are confronted by a horse coming toward you stand still and tall, and the horse will avoid you.  If you try to jump out of the way, you may find the horse making the same move.
• Generally horses don't bite and kick, owners of such animals will warn you to stay away.  If in doubt stay away from the hind legs,but there is no need to leap out of the way.
• If you are unsure of what to do when a horse is approaching, your best course of action is simply to say hello and ask the rider. 

 

Things that rustle, flap or move quickly tend to trigger a horse's prey behaviour - run from danger or defend yourself if you can't run.