1 Stress echocardiogram: This is an echocardiogram that is performed while the person exercises on a treadmill or stationary bicycle. 2  This test can be used to visualize the motion of the heart's walls and pumping action when the heart is stressed.
Viruses require an active host program to cause damage and infect other executable files or documents, while worms are stand-alone malicious programs that can self-replicate and propagate via computer networks, without human help.
Worm composting is using worms to recycle food scraps and other organic material into a valuable soil amendment called vermicompost, or worm compost. Worms eat food scraps, which become compost as they pass through the worm's body. Compost exits the worm through its' tail end.