I brought two bees from foreign nests (a thousand blocks away) over to an empty beehive by my base, used a lead on them to tie them to a fence post near the hive, and waited for 3 in-game days. The bees will hover around the nest with pollen dripping off of them, but remain outside of the nest no matter what time of day. This same thing occurred with a Bee Nest; they would hover around it, but refused to enter it. Their offspring will enter any vacant hive, however.