Is it likely that this bird is (is it a blue tit? I’m not sure) could be using my umbrella base for a nest. The base is extremely close to my garden door. The birds - there are sometimes two of them - come and go continuously through the day.
A great tit and looks very likely! Have you seen them enter with nesting material
(Pardon the Scottish Accent)
The ingenuity of nature......
It looks very much like a blade of dry grass at the entrance to the ballast fill hole on the first photo.
Your patio base could very well be a new home for a pair of great tits, and they cannot be disturbed. The concerns would be
Unless someone can advise different, I'd be tempted to place something like the patio table over to reduce the chance of rain getting in, and leave the rest to nature.
Mike
Flickr: Peak Rambler