But riders have to be wary of unconscious sendings. Almost all thoughts, emotions and anxieties a rider experiences are translated into images and sent to the ambient. Nighthorses are easily "spooked" and careless human emotion can be destructive. Riders therefore have to control their emotions in the presence of nighthorses. In addition, nighthorses generally cannot distinguish between past, present and future: they interpret and act on whatever they pickup literally. So a rider recalling an accident that happened last week will be seen by his horse as happening right now and will take evasive action. Riders quickly learn to quieten their minds so as to not excite their horses. Riders have to be particularly careful of rogue nighthorses. Wanting something intently, for example, a rider-shelter in a storm, can be picked by a rogue and sent back to you, making you believe, sometimes to your peril, that a shelter is right in front of you.