thief, thieves

Some nouns ending in f or fe change those terminations to ve in the plural, as beef——beeves, leaf——leaves, knife——knives, loaf——loaves, life——lives, wife——wives, thief——thieves, wolf——wolves, self——selves, shelf——shelves, calf——calves, half——halves, elf——elves, sheaf——sheaves.

—I have several reasons for believing that it is not a thief; thieves take more precautions; this one walked heavily in my asparagus-bed.