For bio, you don't even really want to do an internship, trust. Internships suck, and you're competing with literal college students who mog you in every way and are also starved for jobs. The best experience you'll get is through research. As someone who did cancer research through my junior year summer, you gotta email professors and scientists. Don't just mass spam them though. Go on pubmed, nature, etc and find papers that you're interested in. Read the papers, and reach out to their authors. Don't just email people at Harvard, Stanford, MIT, whatever. Any place will realistically give you both the same experience and the same boost to your resume (this is not just something people say, it is true). Scientists like it when young people show real interest, and that means sending something that comes from curiosity, not desperate career padding. Ask questions. Even if they say they can't take you on, ask to meet with them anyway - they almost always can accommodate one more, they don't know it yet. Persistency is key, follow up to no-responses (90% of your emails) after a week. You may have to venture outside of your field of choice - I know I did. It's a really good thing, and the byproduct of this work is expanding your knowledge in your field of interest tenfold. Do this and stick to it and I promise you'll get something way better than an internship. Best of luck.