Why are some cells darker than others?

When the comb is brand new, it is white to light yellow. When the bees make new comb we call it "drawing out the comb." Here is a freshly drawn comb.

The comb starts to get darker as it ages. Depending on what is stored in the comb, it will get darker faster. Honey comb doesn't get very dark because honey and nectar are almost clear and cannot color the comb very much. Cells in comb that are used for baby bees (eggs, larvae, and pupae), however, get very dark. That is because that honeybees, like moths, spin a cocoon when they pupate. This cocoon is made of silk strands that come from the mouth of the larva inside. You can't see the cocoon very well because of that wax cap the worker bees put over the cell when the larva when it starts to pupate. Even when you cut open a cell, it is very hard to see the cocoon because it is so thin and sticks to the wall of the cell like wallpaper. The cocoon is darker than the wax, and it makes the wax cells look darker. Once a bee has emerged from a cell, the cell can be re-used for a new larva, so the next larva will spin its cocoon inside the old cocoon of the last larva. The cocoon layers build up like a stack of paper until the cells look very dark indeed. Here is a cross-sectioned (sliced open) cell with an egg. See all the layers at the bottom? Those are old cocoons built up over years.

The pollen also colors the comb. Pollen is usually yellow, but can be brown, red, orange, white, and even purple.  These colors all get mixed up when the pollen is stored in the cells to make bee bread. The wax gets stained or colored by all the pollen and starts to look dark.


New comb photo from UNL extension.

What's in the cells?

The cells are the holes in the honeycomb. They are all-purpose cubbyholes for the bees. Kind of like your desks at school, they use them to organize all their stuff. What kind of stuff do bees have to organize? Lots of stuff!

These are the baby bees. Each baby bee gets its very own cell. They start out as tiny eggs laid by the queen in the bottom of each cell. After they hatch, they are worm-like creatures called larvae. The nurse bees feed them royal jelly, the shiny white liquid around the larvae in this photo. They get bigger and bigger until they pupate, or turn into a pupa inside the cell. The pupa stage is hard to see because as soon as a larva is ready to pupate the worker bees cover up its cell with a cap. Like this:

The cap on the cell is made of wax like the rest of the comb. It protects the pupa from damage. The pupa doesn't eat, so the nurse bees don't need to keep feeding it. Inside the capped cell, the pupa develops into an adult bee.

Here is a newly emerged honeybee. She has just chewed through the cap on her cell and is poking her head out for the first time. She is still very soft and cannot sting or fly for about 24 hours.

Two other things that bees keep in the cells are nectar and pollen. This is their food. The nectar (shiny watery liquid in the above photo) is made into honey. The pollen (yellow powdery stuff in above photo) is made into nutrient-rich food for the bees called "bee bread." Bee bread is just pollen that has been processed by friendly microbes, kind of like the bread that we eat. Our bread uses yeast (a microbe) to rise and taste good.

When the nectar is made into honey, it will have a lot less water in it. The bees cover the honey cells with a wax cap like they do for the pupating honeybee larvae. The cap looks different, though.

So that's what the bees keep in the cells- eggs, larvae, pupae, pollen, bee bread, nectar, and honey! Everything that the beehive needs is stored in the cells.

Bee larvae, emerging bee, pollen and nectar photo by Flickr user Max xx. Capped brood photo by Flickr user KrisFricke. Capped honey photo by Flickr user willsfca.