Here’s a fun how-to video that I found on YouTube this afternoon. (See below for video.) The rat has learned how to pull up on a string to raise a small bucket or basket that contains a treat. I’ve seen this trick on YouTube before, but this is a nice video because it does a good job of explaining the steps to teach this trick.
This is not something that I’ve taught my ratties, but I definitely think it is something that they could learn! Maybe it would be a fun trick to work on next.
The trainer in the video teaches this trick by starting with the string short and gradually makes the string longer. One thing to notice about this trick. It might seem like you are shaping along a single, linear dimension — gradually making the string longer. However, this is true only if you are focusing on the outcome of the rat getting the bucket.
If you focus instead on the behavior, you’ll realize that the rat’s behavior has to switch at some point. In the beginning, when the string is short, the rat can grab the handle of the bucket to pull the bucket up.
However, once the string gets to a certain length, the rat can no longer pull the handle of the bucket and must pull the string instead. The trainer in the video does a nice job of pointing this out and makes a good suggestion. When the bucket is just out of reach, go ahead and start rewarding the rat any time the rat pulls on the string or makes an attempt to pull on the string, even if the rat doesn’t pull the bucket up. If you reward these approximations, the rat will pull on the string more and should figure out the next step.
Many times, trainers get really stuck during shaping because they think they are shaping along one dimension, but they miss one of these points where the behavior must “switch.” This often happens when we focus on outcome, rather than the actual movements that the animal must perform to accomplish the task.
Be aware of the movements that your animal must do at each shaping step. If there are points where the animal must switch from one set of movements to another, include steps in your training plan to teach the new movements. Don’t leave these points up to chance and hope that the animal will be able to figure it out, as this often leads to frustration for both the animal and trainer.