Many volunteers are loyal to one or more projects - giving up several days a month to work in a range of weather conditions, to ‘do their bit’ for the environment. Many of them do it for a variety of reasons, but they rarely question whether their work makes an impact, because they see the project site changing in front of their eyes, and see the changes across multiple months and years. I characterise these volunteers as bumblebees - they keep coming back to the hive to do more work.