If your boa is a locality, check the area that it comes from.

The island species often rely heavily on migrant populations of birds. Avian prey is more than likely taken during those periods. You can find excellent photos and videos of certain boa species, not necessarily or always boa constrictors, take bats.

Boa constrictors will eat iguana and native squirrels plus a host of other prey. Wild prey is active and lean. Not like our fat captive raised prey.

The list is long and probably varies depending on many factors.

In captivity, variety is good. Quail, rats, and rabbits are good choices.

There are some very long lived, healthy boas in the hobby. If you see somebody with a boa they raised up from a baby to over 20 years or more, you may want to pay attention to their practices!