Should I frass this?

Karl-- i haven't run out of people we can torture with this pic. as long as it retains the ability to inflict pain, it serves its purpose well. more importantly, i'm just learning about flies and fly scientists and do want to push the limits -- to understand what can/cannot be IDed by whom

The general shape is similar to Stomoxys calcitrans. I can't tell from this angle. The presence of a long syringe like proboscis would need to be present. The tendency to lite on vertical surfaces is another stable fly behavior.

These are dreadful flies which will bite dogs, horses, humans...and extract their blood!

...is such that even career dipterists are often unable to tell family