What do the following words have in common that has nothing to do with their meanings?

FLIES

SEATS

STONE

THEIRS

SHIVER

 

Answer:

 

You can behead and curtail each word and still be left with a valid word:

 

FLIES - - - -  LIE

SEATS - - - - EAT

STONE - - -  TON

THEIRS - - - HEIR

SHIVER - - - HIVE