Training Science Articles:
I wanted to talk a bit about food related anxiety... Mugging and invasive behavior, panicky or over-excited around food.
Most horses start out at least a little thrilled about the clicker training experience. Teaching a safe alternate behavior to mugging (standing facing forward or looking away or backing up or tucking their chin) is a fantastic way to keep us safe. One key element in this first behavior though MUST be relaxation. A horse can tuck their chin or look away or stand facing forward, but be boiling over, trembling with excitement.
What's wrong with too much excitement, we want them to be happy don't we? We want our horses focused on learning, thinking, processing, seeking, trying new behaviors. This can't be done when the horse is over-threshold (in any direction, fear, anxiety, or excitement).
Ok so we want relaxation, what if we can't get it? What if our horse is more extreme than "most"...
The first most important change was NOT starting a session unless they were calm. Starting a session while the horse is at the door buzzing and pawing and tossing his head, would obviously only reinforce this behavior - so starting while he was eating hay and being a horse reinforced that. Also finding times throughout the day where he was off being a normal horse, eating, drinking, napping, whatever, and tossing him a big handful in his bucket, then keep moving.
Working outside on grass helps a lot, or with hay available during the session to provide them options. Starting a session just after a hard meal helps satiate them. It's important to remember that because a horse is designed to eat 24/7 gaps of time without food leaves them feeling 'starving' which induces that anxiety. Slow feeding options for both hard feed and hay can help ease this starvation feeling.
This may vary per horse, in most cases I've seen, LARGE handfuls of food with a high rate of reinforcement eased his worries. He was satiated quickly and we slowly reduced our handful size throughout the session - but it helps take that "I'm starving" edge off. Other horses may do better with smaller amounts fed at a higher frequency, you'll have to experiment to find your horse's comfort level. Of course using low value treats helps too. While scratching may be a good temporary reinforcer to use, it's ideal to get a horse comfortable and safe around food rewards (for efficiency and easing their stress over food throughout their life).
The last thing that proved to be incredibly valuable was toys... Particularly toys that provided food. You can use buckets with holes, hanging cones, hay nets, forage/treats hung up, cardboard boxes, plastic bags with holes - anything they have to shake, rattle or roll to get treats out of. Many more ideas in the [Enrichment] file. Please ensure your toys are species safe, no loops large enough to capture a hoof or anything they could potentially choke on. These toys takes the pressure off humans as being the sole providers of all things good. Make sure there are toys in the pasture, but especially valuable in stalls. This is not only entertaining, but it allows horses to express their natural foraging behaviors, pawing, rolling objects, shaking trees and so on. It encourages problem solving and creativity, which is great for clicker horses! Most importantly it puts the horse in control of their environment and their food reinforcers. This sense of control brings comfort and confidence.
I hope this helps everyone!