Why do horses shake their head "no" even when saddled?

I was playing survivalcraft this morning. I was riding my black horse when all of a sudden it stopped. When I attempted to make it move again it shook its head no. The horse was already saddled. What's going on? Is it a glitch? Is the horse tired? What?


They are being stubborn. You have to throw a rose/red flower at them to start moving, and when they are nodding their head then you can get back on and ride again!