What characteristic helps in identifying bat rub marks?

The characteristic that helps in identifying bat rub marks is associated with the smooth, polished appearance of surfaces. Bats often roost in small spaces, and as they enter and exit their roosting spots, their bodies brush against various structures. This repetitive contact can create a distinctive, glossy sheen on surfaces like walls or entryways, which is indicative of bat activity.

The other characteristics mentioned do not accurately describe bat rub marks as effectively. For example, feathered edges are typically associated with bird entryways rather than bats. Sticky yellow droppings might suggest the presence of a different animal, and while bats do produce droppings, the presence of white chalky material is commonly linked to minerals or other environmental factors rather than directly indicating bat activity. The smoothness and polish result from the oils and fur of the bats' bodies, making it a key identifying feature.