What is the difference between Africanised honey bees and other bees? 

The most notable difference between the Africanised honey bees and other bees is their increased aggressiveness. When a typical honey bee hive is disturbed they will send out a few bees to defend against possible intruders; Africanised hives will send out hundreds of bees which will defend a much greater area around the hive. 

Is it possible to tell the difference between Africanised honey bees and European bees just by looking at them?

No. The best way to tell the difference is through laboratory testing.

What is a swarm of bees?

A swarm is merely a honey bee colony in search of a nesting site. Each spring a beehive who has grown too large will raise one or more new queens. The old queen will then leave with a portion of the bees. This swarm of bees will usually land on a tree or side of a building while scouts search for a place to build their hive. Swarming bees are not normally aggressive, but unless you are an experienced beekeeper it is best to avoid getting too close to swarming bees.

Why are bees so important to our ecosystem? 

According to the U.S. Department of Agriculture honey bees pollinate 80% of our flowering crops which constitutes 1/3 of everything we eat. Bees are also vital to the reproduction of clover and alfalfa, which feed grazing animals.

How long does a honeybee live?

The life span of honey bees varies, depending on the role of an individual bee within the colony.  All being well, a honey bee queen could live for 3 to 4 years, as long as she is free from disease. Workers raised during the spring or summer months may live for 6 or 7 weeks.   Their lives are especially busy, with lots of hungry larvae to feed, and honeycomb to be produced.   This is when the colony is at its most productive, with workers busy collecting nectar and pollen for feeding the colony.   At the most, drones may live for up to 4 months.

How many eggs can a queen bee lay in her lifetime?

The Queen Bee can lay approximately 1,000 to 1,500 eggs a day.

How many bees are in a typical honey bee hive?

Between 20,000 and 60,000 bees live in a single hive
Read more at http://www.arcamax.com/knowledge/trivia/s-314332-953816#k9JPwueb3hVLeF1k.99
Between 20,000 and 60,000 bees live in a single hive
Read more at http://www.arcamax.com/knowledge/trivia/s-314332-953816#k9JPwueb3hVLeF1k.99

Between 10,000 and 60,000 bees live in a typical bee hive.