Final answer:
The nurse's first action should be to clean the bat bite wounds with soap and water to prevent infection, followed by consultation and possible rabies prophylaxis.
Step-by-step explanation:
When a client arrives at the emergency department after being bitten by a bat, and the nurse observes small, nondraining puncture wounds, the first action the nurse should implement is to clean the wounds with soap and water. This step is crucial for preventing infection and is generally recommended before any other measures, such as rabies prophylaxis treatment, are taken. After cleaning the wound, consulting with an infectious disease specialist and possibly beginning rabies prophylaxis treatment may be appropriate, particularly given the high risk of rabies transmission from bats.