Oak Apple?

We have quite a few oak trees and these are on some of them. It is quite soft and squishy . I have only noticed hard oak apples in the past, but I wondered if this was the beginning of one, Some are more colourful than this one having more red and some are more brown. I shall watch their progress.
next door have a swallow's nest above their front door so if it is allowed to stay there should be good Blip opportunities. I feel a bit guilty being pleased as it has made a dreadful mess of their letterbox and doorstep already.
Better weather today and I got a bit of gardening done. I don't think it will last!