Bid Day and Bid Night are dry at UCF. The chapters go out to celebrate around Orlando at dinners or attractions like House of Blues, Planet Hollywood, Disney Quest, Hard Rock Cafe, etc.
These are sisterhood events.
The fraternity guys hang around outside of the sorority houses when the new members make their run down Greek Park. Outside there is a lot of chaos as the new members join their chapters, find their Bid Day Buddies and take photos with a professional photog.
Some chapters rent a bouncehouse or get a local radio station to park their party bus and broadcast from the street. It's a lot of fun to run across the street and take photos with your friends in different chapters!
The fraternity guys fade out once the Bid Day festivities move into the actual houses. They aren't part of the actual Bid Day... they just traditionally park themselves outside the door of the Homecoming Partners/Girlfriends/Lil or Big Sis's chapter to hang out for a little while and congratulate the chapter on a great recruitment.
ETA: a lot of other schools get really dressed up for Bid Day. At UCF, Bid Day is split into two parts. Actual Bid Day is super casual with t-shirts and shorts-- this is the first time you get to wear a letter t-shirt!!!

After a break where everyone goes home and changes into cute dresses, we all go out to dinner. It isn't unusual to run into another sorority celebrating their Bid Day at the same venue.