compass. Truly. As a traditional navigational tool, it’s simple to use, it’s light to pack, it easily fits into your hand, and it requires no plugs, batteries, or charging stations. But let’s just say that, hypothetically, you discover that you’ve accidentally left it at home. It’s not ideal, but it’s not a serious problem, right? After all, you’ve got the nature knowhow to get around. You know, for instance, that moss only grows on the north side of a tree. But while everyone’s favorite clumping green flowerless plant tends to prefer the shade, which may technically be more prevalent on the northern side of a tree in the Northern Hemisphere, there’s no rule that says the stuff can’t grow in mats as thick as it wants wherever it wants. Moisture levels, other sources of shade, weather conditions, and Mother Nature’s seemingly infinite cabinet of curiosities can all encourage moss to grow on the north, south, east, or west side of a tree—or any combination thereof. If you rely on moss to find your way, chances are better than great that you’re not going to find your way. If you do, it’s more luck than navigational help from bryophyta. One natural navigation expert has added an interesting wrinkle to the moss theory, though, noting that a thorough knowledge of the environment—including such technical details as the depth of surface gradients and the height at which moisture from ground evaporation tends to dissipate—actually can allow a lost hiker (or one simply seeking a challenge) to use moss as a fairly reliable compass substitute, giving the astute observer an idea of which way is north. The science, biology, and trivia knowhow necessary to properly read what the moss is telling you may be complex and still involve some luck and guesswork, but nobody said nature would make things easy. (That’s what your compass is for.) In North America, hikers with a working knowledge based more in animal than plant life can look to migrating birds to help determine which direction is which. In the Northern Hemisphere, birds that undertake the epic journeys twice each year tend to move south in the winter and north in the spring, following abundant food sources, including insects and plants. Geese are the stereotypical living compasses, as their distinctive V-shaped flocks literally point the way toward whichever direction they’re heading. Of course, as with everything else wild and unpredictable, a group of geese isn’t necessarily going to be heading due south. The birds can be swayed by the sight of a welcoming body of water or a promising patch for foraging, or they simply might not care whether they’re heading in an exact cardinal direction. Even the sun rising in the east isn’t a perfect direction-finder. Thanks to the fact that this ball of spinning rock we’re on doesn’t sit straight in space in relation to the star it orbits, we get variations in exactly where that bright orange ball breaks over the horizon at dawn. Still, a little almanac-like knowledge of the time of year and your place on the globe can help you more precisely determine your direction. Don’t feel like brushing up on avian migration facts, ideal growing conditions for moss, or the exact angle of our planet’s axis? Nature is great and all — it’s why we visit it so often — but invest in a compass (and don’t leave it at home).