The temperatures in active volcanoes are much too high to support life (e.g., about 1000 ◦C or more in molten lava), but fumaroles and hot springs associated with volcanic activity provide much lower, more suitable temperatures.

It has been proved that, for a connected automaton of size at most~3, or when the automaton is not bireversible, the generated group cannot be Burnside infinite.

Most birds are diurnal.

Although the emulsifying properties of quillaia are mentioned in every text-book, yet its advantages do not appear to be generally known or made use of.