I think they start way too many early in Spring . . .
It's not Spring below the equator.
Chilled brood is common in the spring in the north-east USA.
In the fall drone pupae are no longer useful and are disposed. Are they tossing drone pupae or workers? What do they have for stores?
How many hives do you have?
What are the workers bringing in?
How strong is(are) the hive(s)?
How many frames of brood/honey/pollen/drawn comb???
If something looks unusual, you should inspect the hive unless you already understand what is happening.