I visited the apiary where Colony 11 is sited this evening. They are still angry 24 hours after I reorganised the hive in a failed attempt to extract the lid of a nucleus box. They bumped against head when I came within 5m. When I had my veil on and got closer they went into attack behaviour (high pitched buzzing; staying in one place on the veil; jabbing movements with their abdomens). I hope that they calm down and don't spend the season being angry.