No it wasn't aliens, it was a plant known as Azolla. Just watch the video, it'll make more sense.

The 2mm-long beetles feed solely on the azolla plants, originally from North and South America. It follows action by local anglers to pull half-a-tonne of duck weed from a stretch of the canal at ...

Is the floating freshwater fern commonly called Carolina azolla the potential answer to global food insecurity or a possible threat to humanity? On the heels of a study published earlier this year by ...

BBC Inside Science A special programme on plants and their pollinators, poisons and pests Azolla – a tiny ancient fern-like pond weed A tiny ancient fern-like pond weed that could have changed ...