At the time of writing we've attempted to nest 4 bumblebees, without success. Ok, to be fair, one of them got away while we were trying to encourage her into the box, but we got three of them in there and none have stayed. (Two bufftails and one redtail).
There's a ton of advice on the internet, but lots of it is conflicting, so sometimes it's hard to pick your way through it. I think the best advice I have seen is the most recent: "think like a Queen".
It's obvious when you think about it. A queen looking for a nest is looking to satisfy a number of basic parameters; and getting those wrong is surely going to put her off. The obvious case in point, is putting the bee in the box and then blocking it up for 24 hours. We've tried this each time so far, but I've been very uncertain of it as a strategy on several levels.
For starters, the bee hasn't discovered the box and its entrance itself, so it hasn't gone through its "process" of ticking the boxes to find a nest that suits. Secondly, it's trapped in there for 24 hours! If it was me, I'd panic, and even if I got out, I'd be paranoid it would happen again. I'd never make it my home.
It seems my feelings are backed up by the latest piece of advice we got from an expert, which I've re-produced below.
A lot of other things we are doing right - but as this is our first year, it's hard to be sure of some things: like what's the right amount of nesting material for each individual species of bee? We'll just have to discover that by trial and error - which is why I want to get another box (to do more trying).
So, the latest set of tips:
- Site the box for the bees in your garden. So if you have ground nesters and underground nesters put the box on the ground. You can fool underground nester that the box is underground by using a bit of hosepipe from the entrance. Abovegound nesters tend to have smaller nests, so if your box is big fill it up with nest material so that there is not too much free space.
- If it is well sited, but has had no success, leave it out over winter. If a mouse or vole or even a bird nests in it that is good. Leave the nesting material if it is dry, and add more if needed. They seem to be attracted to old mammal nests.
- When the queen is nest searching she needs food nearby. So the promise of food to come means nothing. Make sure there are some flowering plants during the nest searching time. If you don't have any, a pot of flowering heather near the box is the easiest solution. You can always move it once your other flowers are in bloom.
- Don't confine the queen. Let her come and go as she pleases. Believe it or not good sites are fought over to the death by queens. She will never return to a site where she had difficulty getting out - what would happen if she laid eggs in such a site? So think like a queen.
- Do not disturb the box by looking at it. I know the temptation is strong. Wait until you see a queen go in with pollen in her baskets - this means she has chosen. Then, and only then should you very gently observe her if you must.
One of the other things we are going to try is going to a local pet shop and asking if they have any "mouse litter" we can put in or around the box. The evidence of rodents having used the box is apparently a great encouragment to the queen that the box is dry, warm and safe.