Certain species of wild oats have a special seed dispersal system that looks as if the seeds are walking on the ground looking for suitable soil to take root in.

Modern-day oats (Avena sativa) have been drastically altered through domestication and are entirely dependent on humans for their survival. Not only do they need to be drilled into the soil, but the seeds remain attached to the panicle to make them easier to harvest and minimize seed losses. Wild oats, on the other hand, are a completely different story. They have evolved highly specialized anatomical features that actually assist the spikelets housing the seeds to move on the ground in search of suitable rooting soil. This amazing ability has won the plants several nicknames, including “Animated Oats” and “Animal Oats”.

Photo: Matt Lavin/Flickr

Once the oat spikelets fall to the ground, two long twisted awns with a fixed 90-degree bend at the mid-point start to rotate, making it seem like the structure is moving consciously. It is only an illusion, as the movement is a purely physical process affected solely by daily wet-dry cycles, and not some plant consciousness.

According to this informative video I found while researching this evolutionary trait, in the evening, as the sun sets, moisture from the air condenses onto the spikelet surfaces. The part of the long, bent awns closest to the seeds are made of twisted tissue, and one side absorbs moisture and swells, while the other remains dry. This causes the awns to unwind and push against whatever surface they are leaning against, in an action so strong that it actually causes the spikelet to move.

But even though this “walking” is not conscious – the spikelet will move the same way under the right weather circumstances even if the seed inside is dead – it serves a very specific purpose. The constant movement facilitated by the daily wet-dry cycle increases the chances of the spikelet ending up in the shadow of a stone or in a soil crack, somewhere with increased moisture that can help the germinating embryos survive.

The movement of animated oats is just one of the fascinating evolutionary traits we’ve featured on Oddity Central over the years.