Scientists who study social insects can determine how individuals in a colony spend their time. Individuals working on a task are engaged in productive output. When colony size supports division of labor and individuals focused on a single task, those workers accomplish more.
Imagine a colony with a small number of individual workers that must transition between tasks. In insect societies as in human societies, worker transition from one task to another is not instantaneous. The tasks may be spatially separated and workers lose the time in transit between tasks. Social insects must receive and process the cues from the environment that motivate them to perform a task. This also takes time.
From simple models, we can understand that a worker with 2 tasks that require a 10 minute transition period between tasks, would only spend 80 minutes working and 40 minutes in transition if the individual transitioned between tasks four times in a two hour period. An individual specialized to only one task would require on one 10 minute transition and would do productive work for 110 minutes in the two hours, a half an hour more work every two hours. Workers in small colonies must attend to multiple tasks. In larger colonies, multiple individuals can each specialize on one task and accomplish more.