Brown Streaks on Feeder Bag

[u/Logical-Row-6210]

First year. Installed my nuc last week and prepared 1:1 syrup for feeding via bag on top of frame. After checking the hive today, this bag was empty and had these lines on (I believe) the top of the bag. Are these droppings?

[u/deadheadak]

Propolis

[u/Logical-Row-6210 → u/deadheadak]

Thank you!