Grey squirrels remember how to solve puzzles for two years

Daily Mail - Science & tech 

If you have ever hung a bird feeder in your garden only to find it emptied by a squirrel minutes later, you'll already know the pesky rodents are smart. Now scientists have shown that squirrels can remember problem-solving techniques for long periods and can apply them to new situations. Research found grey squirrels quickly remember how to solve a problem they have not seen for almost two years, and also quickly work out how to use those skills in a redesigned version of the same test. Animal intelligence is generally judged by how well a creature can adapt to its environment and make use of resources around them. Squirrels have shown they can live almost anywhere, by spreading from North America to other regions, including the UK where they have all but replaced the native red squirrel.