True or False: The obvious sign of anobiid infestation is the accumulation of powdery frass and tiny fecal pellets.

The statement is true. Anobiid beetles, commonly known as wood-boring beetles, leave behind specific signs of their infestation, which include an accumulation of powdery frass and tiny fecal pellets. This frass is created when the adult beetles bore into wood, feeding on it and subsequently excreting the sawdust-like material. The presence of this frass is a clear indicator of an infestation, as it can often be found near the exit holes of the beetles or on the surface of affected wood. The observation of these signs is critical for identifying the presence of anobiids, allowing for timely intervention to prevent further damage to structures.

Other options suggest conditions that would either limit the visibility of the infestation or note unusual situations, but the accumulation of frass is a well-documented and standard sign associated with anobiid infestations in typical scenarios.