Beech 99 planes are small short haul 'feeder' airliners.
Often they are used for small parcel freight courier services.
It is typical for FedEx type organizations heavy planes to fly in to a major hub and then transfer their parcels onto smaller planes for more localised delivery.
This is like a big 18-wheeler delivering to a depot and transferring its cargo onto smaller trucks.
There is often a surge of flights at various times during the day and especially early morning.
UAS Transervices, Wiggins, and Freight Runners all fly these services.
All looks pretty normal.