V at n
II.13 The 'work' group
These verbs are concerned with working. The prepositional phrase indicates what the work is concerned with.
Not surprisingly in a large organisation, some scientists beaver away at what are, as far as the company is concerned, even quirkier projects.
He seemed destined to follow his father's path in life: laboring at menial jobs, earning just enough to support his family.
In the case of work, the preposition at is sometimes followed by an '-ing' clause.
labour toil work beaver away toil away work away
There is no magic cure. It's up to you. You just have to work at breaking the habit.