There is a desert village without any houses with bed

Today I find a special village（seed:-511445118,X:136,Z:135) with three villagers and a iron golem.There is a farm and three houses with workshop blocks,but there aren't any houses with bed.

When I use the clock,the villagers have to stay at their workshop.When I put a bed,the villages stay beside the bed and one of them claim it.A villager sleeps on this bed and other stay near it at night.