Basically, the only reason to catch a Bidoof is to fill out your Pokédex.
Every generation of Pokémon games has its own personal version of Rattata, essentially rodents and vermin that crowd the starter areas and are generally useless in battle. Generation IV's Rattata is Bidoof, a cute little beaver that evolves into a slightly larger beaver (Bibarel) at level 15.
While Bibarel might have
an advantage on Raticate thanks to not being a basic Normal Pokémon (it's Normal/Water), it falls considerably short when compared to pretty much any other Pokémon from the fourth generation. Bidoof might be cute, but its low stats and uninspiring moveset make it an easy Pokémon to leave behind.