Certainly a normal empty jar would pose no problem for a bee to fly in and out. Like most insects they do tend to fly towards the light and upwards - but if that fails then they try other directions albeit on a fairly random basis.
The weight of an empty jam jar can vary depending on its size and material. On average, a small empty jam jar may weigh around 100-200 grams, while a larger jar may weigh 300-500 grams.
A bee fly is a member of the fly family Bombyliidae, with adults which look like bumblebees.
In the winter season it remains empty
Ant, bee, fly, bug.
Fill 3 qt jar, and empty into 5 qt jar. Fill 3 qt jar again, and empty 2 qt into 5 qt jar, 1 qt left.
Rain or Condensation
If the bee was still alive, it couldn't have been in the jar very long. Are you sure it wasn't trapped there when the jar was last opened?
ANSWER It is probally a bee fly
bee
yes u can but u have to have little holes in the jar
no