The old saw ‘a place for everything, everything in its place’ is something that we all give at least lip service to. When someone comments about those unruly piles of papers on and around one’s desk, they will usually get the response “I know where everything is, don’t move anything.”
How does your refrigerator or food storage cupboard look? Everything clearly visible or the oldest things pushed to the back, out of sight? But of course you know that they are there, and you will get round to using them before it’s too late. It is not just us who think we know where we put important things. (Things that we can’t find are always important.) Animals do too.
Birds, squirrels and mice, for example, store food for the winter, and have to remember where they put it. Many trees are there, standing in their majestic glory today because some squirrel sat scratching its head, muttering, “Now where did I put that acorn?” Insects are generally more organized. Honeybees live in the middle of their store cupboard and spiders wrap up their food in silk and hang it up on their web.
A new study by Rodríguez and Gloudman in the journal of Animal Cognition was directed at the memory of spiders. They chose the Bowl and Doily spider for their study. This spider spins a bowl shaped web above a non-sticky sheet. The bowl catches its prey and the spider then bites around the prey so it falls through and is stored on the sheet underneath.
In the study various bits of stored prey were filched by the investigators and the spider was watched whilst it searched for it. The higher quality and larger the prey stolen, the harder the search, indicating that the spider was well ware of what she had lost and where it had been. The report didn’t mention if they returned the stolen property or fenced it elsewhere.
