Tree Bumblebees

[A McLee]

There are 2 nests near my house under the eves. For the last few days there has been a lot of activity outside them, not carrying pollen or nectar, but large specimens hovering around and chasing each other and just sometimes entering the nest. What is going on, please anyone?
Ali McLee

[Mike Tucker]

Same in my sparrow box, the noise coming from the box yesterday was incredible.