here the bees are 1 month late, but this sun has bought them out now. Numbers do seem down though, the foxgloves are normally a hive of activity by now, but only seen red arses and bumble bees so far, no honey bees yet.
What wood are you thinking of using ? as most wont last long at all.
I've done it before with already slightly hollow wood and just burnt it out more, then found plastic pots that fit the hole.