I’ve used cardboard boxes for years. They do the job, but they’re not exactly very tolerant of the occasional rain shower and if I’ve not used one for a while it seems to disappear to be used for other purposes.
So, I made a decent wooden one (two, in fact), with a 3d-printed entrance.
And a slide-out solid floor with a mesh floor above it, for ventilation.
When collecting the swarm the solid floor is left in so the bees don’t get confused and hang onto the outside.
