Garters aren't gregarious or communal animals (except for during mating/brumation). Sometimes they'll be found together in prime habitat, but it's not due to any sort of "herd" mentality. Therefore, it's certainly not NECESSARY to have more than one garter... The problem is that they're just so stinkin' cool that it's hard to limit yourself to just one. More power to you, but it would take more will power than I have

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Rick
P.S. Welcome aboard, Odie.