HCA: Hermit Crab Association

I hear Chirping pretty often from my tank and I always run over to see if everything is alright and nothing is usually happening. Any ideas fi they are just talking or fighting? I thought I read they only chirp if they are upset. Thanks in advance.

Sometimes it's hard to tell if there's really a fight going on or if they are just communicating. Whenever I feed one of their favorite foods and a lot of crabs are up swarming it, I hear chirping all night. I've only seen chirping and fighting one time, and I didn't do anything I just watched and both crabs just backed off and walked away.