Hoi An is a wonderful little place to visit but like me if you have an adversity to rats you might be disapointed or even distressed!
We stopped at 8 restaurants to either eat or drink during our 2 nights there. In 4 of the eateries we had rats within a few feet of us either under nearby tables, in the rafters or along the walls. We also saw several near the river after dark. We spent 3 further weeks in Vietnam and only saw one other one in our whole trip!
Unfortunately It completely spoilt my time in Hoi An, so if you do suffer from a rat phobia and visting Hoi An you might need to eat in upstairs venues and dont stay out too late.