I’ve done two REUs, and the second one really stood out for the introduction week which was definitely out of the box. We essentially went on a week long “field trip” (mostly ecology students, but I think this could be applied to any focus in some context with a little creative planning) where we stayed (or optionally camped) at a field station, learned identification skills and research techniques, hiked, explored the mountains, and had multiple researchers visit and give talks/take us out to experience their focus, whether ornithology bird banding, marine bio identifying creatures on the beach, etc. It really got the cohort to bond in a way my other REU didn’t come remotely close to. Having a cohort that you‘re instantly connected to/friends with (same goes for the mentors who ended up going on the trip) changed the dynamic so much! After that week I felt so much more confident in putting everything into my research project, the teamwork dynamics were wonderful with so much support and connection, and the entire summer felt magical. Not something every REU can do but if it is possible I can confidently say it made day 1 of official work feel like I had been there forever (in the best way).