The arenicola (or Solum harenosum) belongs to the marine infrafauna: that is to say, species which are buried beneath the ocean sediment. There has been much speculation about the reasons for this: some ethologist point to an incorrigible tendency towards procrastination, incompatible with the daily obligations of the seabed; others, to an absence of interpersonal skills – aggravated by the difficulty to articulate words beneath thousands of atmospheres of pressure – which leads it to avoid any social life; while there are those who also stress the fear from which any even slightly sensible being would suffer living in constant darkness, as well as their inability to confront any difficulties, to an extent only comparable to that of the ostriches of the terrestrial environment.