Will pepper spray be effective against a mountain lion? Although pepper spray may be an effective deterrent, you really don't want the lion to even get that close. Maintain eye contact if you sight a lion. Lions like to attack from ambush and count on the element of surprise. If the lion sees that you have seen it and are facing it, it is less likely to attack. If you see a lion DON'T RUN! Running stimulates the predator reflex and may cause you to be irresistible to a lion. Don't turn your back. Lions prefer to attack from behind. Turning your back on a lion invites its further interest.