Numbers of bees throughout the UK have been steadily declining. Bumblebees are important pollinators and it makes sense to protect them rather than destroy them. According to the Edinburgh and Midlothian Beekeepers' Association, bumblebees are not aggressive unless their nest is attacked.
Leave the attic soon after you discover the nest. Close the hatch door. This is so that the bees do not start to invade the rest of the house.
Refer to the link in Resources giving information about free bee swarm collection. This is a list of bee keepers and others throughout the UK who are willing to collect bees. These collectors have the protective clothing, equipment and experience to be able to remove bees safely. They will remove them from your premises and take them to alternative sites. Some of the people listed charge a fee but many will collect bees for free.
Find a person in your area who is willing to collect bumblebees. Some of the people listed are only willing to collect honeybees. If you cannot find anyone in your area willing to deal with bumblebees, look at a nearby area. Some of the people listed are willing to travel to other counties to collect bees.
Contact a collector and explain the situation. The collector may want to know how high up in your loft the nest is. How full of things you loft is may also be of interest to the collector, as this will affect ease of access to the nest. Whether the attic has a light is also likely to be of significance to the collector. Information about the size of the nest might also be important. Give the collector as many facts as possible so she can prepare properly.
Ask how the job will be done. If bee smoke is going to be used in your loft to calm the bees, you need to be aware. You need to be assured that the job will be done safely. If you are satisfied with what you hear, make arrangements for the collector to come to your house. Give your address and any tips you may have about getting to the house and where to park.
Clear access to the loft hatch while waiting for the collector to arrive. Move any obstructions out of the way -- such as furniture on the landing -- to make things easier. If you need a ladder to get into your loft, have it set up and ready. Keep the hatch door closed, especially if there are children in the house.
Welcome the collector on arrival and show her to the loft hatch. Discuss the route the collector will take through the house when she has collected the nest. Ensure children and pets are out of the way, in another part of the house. Leave the collector to get on with the job.