Do lemmings actually commit mass suicide?

I've recently joined Lemmy and was reminded of this old fact I used to hear about all the time that lemmings will commit mass suicide by jumping off cliffs when they migrate (lemmings being the namesake of Lemmy, I think?).

Do lemmings actually do this? Because I think it would be funny if a social media software was named after an animal that's literally known for mass hysteria / mob mentality.