First, some disclaimers: what I am about to say is relevant for someone thinking about graduate school in Ecology and Evolution in the United States. Some of the information might be relevant for other fields or regions but others parts will not. Second, everything I am going to talk about here is based on my background applying to and attending graduate school, and represents my opinions. I was the first generation in my family to go to college, let alone graduate school, so this is mostly what I have learned and picked up through my personal experiences, and the experiences of those around me, in the last several years. I recognize that other people have had different experiences and would disagree with some of the things I am going to say. I welcome these differing views and opinions, and am happy to open a discussion. With all of that said, I hope some part of this can be helpful to you!
I am at the airport, waiting for my flight home after the first semester of my PhD. This time last year I was visiting prospective labs; for any anyone starting that process now I want to share questions you should consider asking prospective advisors and lab mates!
First, most important: Are you happy? This is a question for everyone you meet! You can ask more specific things like: Are you happy in this lab, in this department, in this city? People will be honest, and you can start to get an idea if you would be happy there.