Blue Tits will often come to a nest box simply to pick small insects off it. A box that they feel unsuitable for nesting will often be investigated in this way as many of the small insects they feed upon will be found on the wood of the box - sometimes inside it.
A successful nest box needs to meet a few criteria:
- It should be out of direct sunlight. A box fully south facing will not be used. You will see guides suggesting having your box face north or east but the most successful nest box in my garden faces west and is shaded on its southern side.
- There should be a landing perch nearby. Blue Tits returning to the clutch with food will not fly directly into the box. They perch briefly on a nearby fence or branch, typically 2m - 5m away. They look around for potential predators before entering the box. So, place your box near bushes or your garden fence.
- The entrance should be clear and open. Despite the previous point, don't put the box amongst foliage. Place it at a height of 2m - 2.5m from the ground.
- The location should be quiet. Don't put the nesting box too close to a feeding station. Again, my most successful box is about 10m from my feeding station. The birds seem happy at that distance - I've seen them go from box to feeder and return to the box with food. I've given up with boxes within 5m, they've never been used.
I wouldn't put food or bedding into the box. In fact the opposite, after a successful fledge, clean the box, removing the old nest.
There are good hints around the web for Blue Tit nesting, e.g. from the BTO.
I have had a few successful fledges from my garden. Some boxes have been up for two or three years before they were used, others are used every year. Be patient, and good luck.
