These Bees Were Planning to Expand
The more bricks Glover removed, the more bees he was uncovering. The walls were infested with bees, and judging by what he had uncovered of the hive, they had been there a while and were planning to stay for a while longer.
Wild bee hives can vary in size depending on where they are constructed, how much space the location has, and how well the site can accommodate the weight of the hive. In this case, with so much wall, these bees could have been planning to expand their hive extensively.