[This was written by Fran Siebrits and published online by Wild Magazine http://www.wildcard.co.za/, 2011]
In a world where predators are as common as crumbs on a loaf of bread, bees have to make their feeding activity as quick and effective as possible.  
For animals that use nectar as a food source, there are two factors that determine their feeding efficiency. The one is the method of feeding – whether the animal is a ‘dipper’ or a ‘sucker’ – and the other is how sugary and runny the actual nectar is.

Sucker-feeders include birds and butterflies, which suck up nectar through a long, thin proboscis. Nectar therefore needs to be less sugary and viscous (thick and sticky) in order for sucker-feeders to be efficient at feeding. Bees, on the other hand, are dipper-feeders – they probe flowers with their tongues and prefer viscous, sugary nectar.

When researchers reviewed data from previous studies on nectar-finding species, they found a clear connection between the feeding method and the concentration of sugar in nectar. Sucker-feeders fare best when slurping up nectar with a sugar concentration of 33%; for dippers the optimal concentration is 52%, making the nectar more viscous. The fact that there’s an ideal viscosity for each feeding mechanism points to optimisation. In other words, flowers may have tailored the sugar content of their nectar in order to attract specific animals.

Bees feed on nectar primarily for energy and on pollen for protein and other nutrients. Both the bees and their preferred ‘flower restaurants’ have evolved together so that they mutually benefit from this relationship. While bees are getting their quick fix of sugar, flowers manage to attach pollen onto the bees’ bodies for distribution. Of all the animal pollinators, bees are the most successful pollen distributors.

Nectar feeding highlights optimisation in nature and is just one example of what happens on a larger, more intricate scale within ecosystems and the environment in general. 

Massachusetts Institute of Technology (12 October 2011). Sugar high for bees. ScienceDaily.
Viewed online [http://www.sciencedaily.com /releases/2011/10/111012124147.htm]

WIKIPEDIA. 2011. Bee. Viewed online [http://en.wikipedia.org/wiki/Bee.htm]