Surface areas on walls, under loose woodwork, between bricks and around other bat entryways often have a smooth, polished appearance. The stained area is slightly sticky, may contain a few bat hairs, and is yellowbrown to blackish brown in color.
cross connections What is a Cross Connection? A cross connection is a point in a plumbing system where the potable water supply is con-nected to a non-potable source. Briefly, a cross connection exists whenever the drinking water system is or could be connected to any non-potable source (plumbing fixture, equipment used in any plumbing system).
Credit: Thomas Barwick Stone Getty Images. A cross-guide coupler is a kind of waveguide. Waveguides are hollow metal cylinders or boxes that transmit electrical current. They are only useful for transmitting electricity if the electrical signal has a very high frequency, which is the case with microwave energy.