Bored as an oyster?

Razor clam, boredom long past

The translation I'm working on includes the phrase, aburrirse como pingüinos-- become bored as penguins? A little sleuthing around turned up the phrase, aburrirse como una ostra or una almeja-- bored as an oyster, or bored as a clam. Bivalves likely lead pretty dull lives (though a razor clam can burrow down 24 inches in less than a minute which, allowing for scale, is faster than many bipeds can travel). A new phrase for me, but evidently a perfectly common way of saying "bored to tears" or "bored to death." Bored silly, bored stiff, bored beyond belief, bored out of one's mind--there's quite a variety of ways to say it in English. My guess would be lots of bored people, looking for colorful ways to complain. Based on the lists I've assembled so far, Spanish seems to have more "bored as an [x]" comparisons, while English speakers seem more likely to be bored into or out of a state or condition.

Idioms are a challenge--to teach, to translate, let alone to employ with any grace in one's own speech. One of my favorite moments from my college Spanish classes was when the exasperated professor, faced with a student's protest--"I'd never say it like that!"--responded drily, "Fortunately, the language is not limited to what you would or would not say." I think we were talking about heartbreak.

But about those penguins. In context, it's a variation on a common theme; the reader of the original would have the standard idiom in her repertoire, and notice the shift. Recognizable yet unexpected. I haven't quite worked out how to preserve that wrinkle in the English, though I'm thinking I might keep the penguins, just for fun. 

I'm seldom bored, but I'll be looking for ways to work the oyster's ennui into conversation.