Real lemmings don't commit mass suicide

Unlike repugicans

Earlier this week, repugican representative Devin Nunes referred to his colleagues in the US House of Representatives as "lemmings with suicide vests". I would like to propose that this characterization is vastly unfair. To the lemmings.
That's because real lemmings, such as the adorable little creature pictured above, aren't actually suicidal. If anything, their problem is that they're just too damn horny. [Insert new political analogy here.]
The problem with lemmings is that they are fertile. Very, very fertile. Unlike a lot of animals, they can breed throughout the year and start having babies before they, themselves, are fully grown. These facts are probably part of why lemming populations in any given area are highly variable. Over the course of a few years, a place will become lousy with lemmings and then the populations will plummet and the cycle will start all over again. What happens to the lemmings that are lost? Lots of different things — including predation, disease, and other problems of over-population — but some of them migrate, leaving home to go start little lemming colonies in a new place.
And here's where the myth has some origins in truth. Migrating lemmings — like migrating birds or elk or wildebeests — move in packs. Sometimes, those packs run into bodies of water, like a lake or a river. Lemmings can swim. So, if they want to continue the migration, there's a decent chance that they'll make an attempt to cross the water. And sometimes that works out just fine. Other times, though, the body of water will be too big or the current too strong and, instead of ending up with a pack of damp and exhausted lemmings reveling in their own triumph over nature, what you get are a bunch of dead lemmings. Technically, yes, they did all walk into the water en masse. But they didn't mean to get killed doing it.
The suicide myth really got going in American pop culture in the 1950s, thanks to Walt Disney. Here's Tyler Moss, writing for mental_floss:

It turns out that there is no proof that an assemblage of wild lemmings would actually drive themselves off of a cliff at all, but rather the myth was perpetuated by a 1958 Disney documentary called White Wilderness, in which the filmmakers manually ran a pack of lemmings off of a cliff to make for good television. The staged suicide turned out to be a critical success, as the movie went on to win the Academy Award for Best Documentary Feature.