Indirect ways of assessing past temperatures, using so-called temperature proxies, take measurements of responses to past temperature change that are preserved in natural archives such as ice, rocks and fossils.
Wikipedia has an article on: Reorder tone. Wikipedia. fast busy signal â(plural fast busy signals) (telephony) An audible signal on a voice phone line that sounds more frequently than a standard busy singal, indicating that no transmission path to the called phone number is available.
Tail flashing is an important visual signal used by squirrels to indicate alarm. It is one of the first signals seen when squirrels discover the location of a disturbing stimulus. When the stimulus is more threatening, the tail flashing is accompanied by vocalizations.