Excerpted from the Manhattan Spectrum:

Sources close to Fast Money say the show’s crew came into the set early Monday morning and found the scat on top of the show’s main, on-air desk.

A producer for the network, who conversed with us under the promise of anonymity, said the network can’t conclusively prove who did it.

“We can’t prove it was Ratigan, or that the scat was human in nature for that matter, but I can’t imagine Najarian or Adami would have been angry enough with Ratigan’s departure to stoop to that level.”

“It’s baffling.”