
There used to be a British Standard for nuclei. This is no longer in use but the requirements set out in that standard are still relevant today. A nucleus colony should:
• have a young, good quality, laying queen. She may be marked and/or clipped
• have all stages of brood present
• be free of signs of disease
• have at least three frames with brood
• have four frames or more fully covered with honey bees
• have at least one full comb of honey (or equivalent) and half a frame of pollen
• contain comb which is in a good, clean condition, preferably being less than one season old
There are many uses for a nucleus colony (beekeepers call it a ‘nuc’ for short):
• For making increase. In this case, the nuc may have a queen cell instead of a laying queen.
• For queen introduction when re-queening. This could be a mini-nuc.
• For housing a swarm
• For storing a surplus queen
• Testing a new queen
• Drawing foundation
• An observation hive is also considered to be a nuc.
A nucleus for sale or increase should consist of three or four frames of brood at all stages with attendant bees. Ideally, one frame of sealed honey but the equivalent nectar will suffice. When transporting, the queen should be caged for safety.

The attendant house bees come from the brood nest of the parent colony and are shaken from frames into the nucleus. You need a sufficient number of house bees to cover three or four frames. If the nuc is to remain in the same apiary as the parent colony, any older foragers shaken in to the nuc will quickly return to the parent colony, leaving only the younger house bees.
Occasionally, foragers from the parent colony will start robbing the nuc, so it’s a good idea to complete the creation of the nuc before placing it in its final location. Keep an eye on it too.
If the nucleus is to be moved immediately to another site, all the bees shaken in, will stay with the nucleus. When creating a nucleus, make sure the entrance is closed until the nuc has been placed in its final location. Some beekeepers block the entrance with grass which will wither, releasing the bees over time. This gives the bees time to form a functioning unit.
Don’t disturb your bees for at least a week but watch the hive entrance for signs of pollen going in.
If the nuc is remaining in the home apiary, don’t feed for at least three days. This is so as not to encourage robbing.
When bees in the nucleus are occupying all frames and stores can be found on the frames nearest the sides of the nuc, it’s time to move the frames and bees into a full-sized brood box. Place the frames from the nuc in the middle of the brood box (in exactly the same order) and complete the brood box with frames of foundation or drawn comb. Be careful not to split the brood nest and after three days, feed with an intermediate strength syrup; 1kg of sugar to 1 litre of water. You can use a frame feeder, contact feeder or a small tray feeder. Feeders; the different types and their uses. Continue to feed until all the frames are drawn. You may even be able to add a queen excluder and super for the bees to store honey!

Advice to a prospective purchaser
Once at the permanent site, let your bees fly. In a day or two, you can transfer them to a full-sized hive.
A nucleus for swarm control
A nucleus hive can be a useful tool in swarm control. If a colony is showing signs of making queen cells, removing the queen to a nuc will prevent the swarm. In the parent colony, reduce the number of queen cells to one or two. If things go wrong, for example, the virgin queen in the parent colony fails to mate or is lost, the queen in the nuc can be reunited with the parent colony.
A nucleus for introducing a new queen
This typically comprises:
• One or two frames of brood and young bees from the colony to be re-queened. Take extra care not to include the resident queen.
• One frame of food
• Two frames of young bees to be shaken in
• The new queen in a queen cage, remember to remove the plastic tab so the bees can eat through the fondant to release the queen
Close the entrance with grass. It’s best to make up the nuc a couple of days before the arrival of the queen. Check the nucleus before introducing the queen and remove any started emergency cells before putting her in.
Re-queening a full-sized colony using the nucleus described above. Method one
• place the old queen from the receiving colony in a queen cage. She can be added to the nucleus later as an insurance
• Check the queen in the nucleus has been released and is laying
• Re-cage her in the queen cage with fresh fondant. Place this cage firmly between two frames in the receiving colony
• Spray the frames with water or very diluted syrup in both the nucleus and receiving colony
• Leave for at least a week, then check the new queen is laying
Method two, using newspaper
This is perhaps a bit easier but does involve killing the old queen unless you have somewhere else to put her.
• Move the nucleus into a full sized box. Add a frame either side of the brood nest (ideally drawn comb) and flank with dummy boards.
• Remove the queen from the receiving colony
• Place a sheet of newspaper over the frames of the receiving colony. Add a queen excluder to stop the paper blowing away.
• Make a few small holes in the paper, ideally with a pin
• Place the nucleus in its new box on top of the queen excluder
• If there were supers on the receiving colony, place another queen excluder on top of the box contains the nuc, then add the supers on top of that.
• Add the crown board and roof and leave for at least a week
• Shredded newspaper at the entrance is a good sign. Check all is well, then rearrange the frames into one box. If you have surplus frames containing stores, scrape off the cappings and place on top of the crownboard under the roof. In most cases, the bees will retrieve the honey and re-store below.
• If, in the unlikely event, there are more than eleven frames containing brood, place the frames with mainly capped brood on top of the crown board under the roof. Remove any queen cells. These frames can be removed when the brood has emerged.
• Fumigate any spare frames of drawn comb with acetic acid or burn them. Fumigating Comb with Acetic Acid.

Full-sized frame mating nucleus
The following guidance on mating nuclei is taken from Ted Hooper’s Guide to Bees and Honey.
The nucleus needs:
• One or two frames of brood and young bees
• Additional two or three frames of bees shaken in
• A sealed queen cell. Remove any cells the nuc has constructed
• Close the entrance with grass
• Leave the nuc alone for three weeks if you can bear it!
• After three weeks, check the queen is present and laying worker brood.
• Once the queen is laying normally, the nuc can be built up by gradually adding foundation and feeding. A five frame nuc with this season’s queen can be sold.
Mini-nuclei for mating
The advantage of a mini-nuc is you don’t need many bees and they are cheap and fun to play with. The disadvantage is that they need regular maintenance as they quickly become over-filled with bees or stores. Bees abscond readily and queen cells will not be raised as too many bees have been lost.

Housing a swarm
A small swarm is best housed in a nucleus as it’s easier to keep the cluster warm and aids the drawing out of comb. After three days, the swarm will need feeding with a frame or contact feeder. Swarm collection and hiving.
Storing a spare queen
A nucleus makes a good home for a spare queen. A spare virgin can sometimes be found if your inspection has been delayed during swarm season. In some situations, bees prevent virgins emerging but they may be released when you disturb the colony during an inspection.
A retirement home
Keeping a productive queen confined in a nuc can extend her life by a number of years. Regularly removing sealed brood results in fewer nurse bees to feed the queen and encourages her to lay. It’s a balance between keeping enough brood to sustain the small colony but not allowing them to get too strong.
Nuclei can be used to draw foundation
Bees in a nucleus will draw foundation equally from corner to corner if fed. Use intermediate strength feed; 1kg sugar to 1 litre of water.
Boosting a colony for a specific crop
A strong nucleus with a young queen can be united with a colony that needs additional bees for specific crops such as taking them to the heather. Remember to first remove the resident queen. Taking bees to the heather.
Pitfalls and problems
• New queens may be rejected, especially if you’ve missed a queen cell.
• Ventilation is important in nucs but not a through-draft
• Drifting can be a problem with nucs so make sure they are positioned away from other hives or orientated in a different direction.
• The nucleus need to be a viable size to over-winter with adequate stores
• A nucleus is easily robbed, so keep the entrance small. Restrict to one or two ‘bee ways’ until the colony builds up
• A nucleus can easily starve. Keep a close eye on stores and feed as necessary
• A strong nucleus builds up quickly so be alert and move to a full-sized hive when necessary.

If you’re starting out in beekeeping and require a nucleus colony, click here.
The page is based on an article by Margaret Thomas which first appeared in BBKA News in March 2015.