When my son (now 20) was two years old we were renting an apartment in a house that had lots of plants and lots of slugs. When we went out for the day Benny would wave back and say "Goodbye slugs". We also had fun watching a couple of them slowly crawl from crack to crack in the sidewalk and would bet on which one would reach the new crack first. One time he said, "Hey, let's name 'em! --- We've got plenty of time!"