Injured employee was working in a small group, removing bags/cages from a dust collector compartment for 3 days. The employee felt sore in EE's left shoulder at the end of day 1 but was feeling increasing pain and discomfort in EE's left shoulder. The employee decided to seek doctor evaluation on 5/16 and did not report to EE's Supervisor that EE was hurt until 7am on 5/16.