My 2 year old daughter has a fever but is still eating and drinking, what could cause this fever?

Infection: Fever in a child is 100.4f/38.4c. A virus is the most common cause of fever in a child. Sometimes there are other symptoms (runny nose, cough, congestion, vomiting, diarrhea), sometimes there is only fever. If she is otherwise acting normally, eating/sleeping fine, and has no specific complaints, nothing needs to be done. Her body will fight it off over a few days. If not, she should be seen.