The honey bee (see image 1:1 and 1:2) varies in color from yellow to black,
have black or brown bands across the abdomen, are approximately 3/4 inch
long and are covered with hairs or setae. A foraging honey bee has pollen
baskets on each hind leg, which will often be loaded with a ball of yellow
or dark green pollen. Honey bees can only sting once, as their stinger and venom sack is left behind as it is impeded in the skins surface. Unfortunately, this action kills the individual bee while at the same time marking you with an alarm pheromone for others to find and continue the attack.
Bumblebees (image 2:1 and 2:2) are are characterized by black and yellow body hairs, often in bands. However, some species have orange or red on their bodies, or may be entirely black. Another obvious characteristic is the soft nature of the hair, called pile, that covers their entire body, making them appear and feel fuzzy. Bumblebees can sting, but unlike a honey bee's, a bumblebee's stinger lacks barbs -- so they can sting more than once. Bumblebee species are normally non-aggressive, but will sting in defense of their nest, or if harmed.
Yellow jackets lack the dense body hairs that are found on carpenter bees and honey bees. Yellow Jackets (image 3:1) do not have the pollen baskets on the hind legs. The yellow jacket is about 1 inch long, and the abdomen is characterized by having alternating yellow and black bands. European hornets are much larger (1.5 inches long) than honey bees and sometimes establish colonies inside structural walls. Yellow jackets have a very painful sting and attack in large numbers. One Yellow jacket may sting numerous times during an attack and like most hornets and wasps stings usually occur on the face.
Bald-faced hornets (image 4:1) also known as the White-faced hornet, are a large (1.5 inches) black and ivory yellow jacket. Bald-Faced Hornets aren't hornets, but pretty darn close, they are wasps. Typically Bald-faced hornets live in wooded areas but may occasionally be found attached to your home or out buildings. The nests are constructed of a paper-like martial formed from chewed wood. Bald-faced hornets construct almost exclusively gray football-shaped nests attached to trees and buildings (but they may exceed a basketball in diameter or even the nest may grow to be larger by the end of the summer). Bald-faced hornets are the most aggressive of the stinging insects and should be avoided at all cost.