looking for accomodation to 3 months erasmus traineesip in Brussels

I am master student in University of Florence, age 26. I am looking for a room, preferably single one for 3 months from january. I prefer to access easily to EU institutions by walk or metro or bus does not matter. I am good with pets so it is not a problem if there is a pet in the flat. I prefer not smoking apartments but if someone smokes somewhere out of my room it is ok too. Gender of flatmates do not matter.