The random pixel pattern superimposed on the picture or the television screen, being visible as a random flicker of "dots", "snow" or "fuzzy zig-zags" in some television sets, is the result of electronic noise and radiated electromagnetic noise accidentally picked up by the antenna like air or cable.
This effect is most commonly seen with analog TV sets, blank VHS tapes, or other display devices.
Since one impression of the "snow" is of fast-flickering black bugs on a white background, the phenomenon is often called myrornas krig in Swedish, myrekrig in Danish, hangyák háborúja in Hungarian, Ameisenkrieg in German, and semut bertengkar in Indonesian, which all translate to 'war of the ants'.
It is also known as ekran karıncalanması in Turkish, meaning 'ants on the screen', hangyafoci 'ant football' in Hungarian, and purici 'fleas' in Romanian.
When it is adjusted to a frequency that is between stations, part of the sound heard is remnant radiation from the Big Bang from around 13.7 billion years ago.