We made our solitary bee box in November 2024, it has Perspex covering slots in the wood so we can watch progress of the eggs and larvae. There is a mud tray on top which bees use to line the slots and seal between each egg cell, they put a final mud plug at the end of the slot.

We noticed the box was being used on 15/5/25 when we saw some slot ends sealed up, we pulled out the cores and saw the slots filled with eggs and pollen.

Female Solitary bees lay an egg with a supply of pollen and nectar in each cell for the larvae to feed on when it hatches. Bees seal each cell with a mud plug in between.

Male eggs are laid towards the front of the slot so they emerge first and are ready to mate the following year.

Female eggs hatch into larvae and eat the pollen, then hibernate for around 11 months in the nest through summer and winter. The following spring, the larvae pupate, turn into adult bees and emerge from their nest.

I made a similar box for my garden which was also partially used.

We will keep watch on the nest box at the mill and keep this page updated with progress.

Graham Bartlett