And further research on drug dogs has shown that subtle body language by their handlers can cause them to alert. Fundamentally, a drug dog alerts because it wa

And further research on drug dogs has shown that subtle body language by their handlers can cause them to alert. Fundamentally, a drug dog alerts because it wants to please its handler (and maybe get a snack). It doesn't understand the tension between drug laws and the 4th amendment, so it can't understand why it should be cautious about alerting. It doesn't understand the consequences of alerting could be a human getting stuck in a small cage for a long time.