The "Transformers" in real life are actually less than an inch big.

Water fleas may only just be microscopic in size, but apparently, they are big when it comes to battle.
A recent study conducted by researchers in Germany found out that water fleas (Daphnia lumholtzi) are able to grow helmets and spines when faced with predators. And what's even more surprising is that the "armor" that they grow depends on the environment that they are in.

So how do they do this? Linda Weiss, a professor at Ruhr-University Bochum in Germany and lead researcher, explained that the water fleas are able to detect scents of their predators through appendages called antennules.

Once they detect the scent, it creates brain signals that trigger the release of the neurotransmitter dopamine. Dopamine will then prompt the release of juvenile hormones that trigger the growth of the armor in different parts of their body.

"As they grow up and moult, juvenile Daphnia can develop formidable 'armor,' including helmets, spines or crests, when they detect specific chemical cues in the water left by predators such as fish, phantom midge larvae and backswimmers," Weiss told Science Daily.

She added that these defenses seem to act like an "anti-lock key system," that interferes somehow with the feeding apparatus of their predators, usually freshwater fish.

And since the armor that they grow depends on the type of environment they are exposed to, Weiss said further research on this subject will help in understanding the composition and population ecosystems, especially in fresh waters where water fleas reside.

Live Science describes water fleas as usually less than 0.2 inches (5 millimeters) long, and look much like translucent versions of the land-based fleas. UK Microscopy notes that they are very common in fresh water: In Britain. you can find about 80 different species, while about 100 species in The Netherlands.

Water fleas are amazing creatures to observe through a microscope. Though tiny, they are interesting to researchers because their internal organs are visible from the outside.