Africanized bee
Africanized honeybees are much more protective of their beehive and more likely to sting.  When one of them is surprised or scared, they all attack together and sting the same animal or person with hundreds of stings.   Actually, their sting is the same as a regular honeybee's, but because they sting all together, they are much more dangerous.  They usually chase their target much farther than regular honeybees, and they stay angry and ready to fight for a longer time.  They have many more "guard" bees than regular honeybees.