Red tide is a phenomenon caused by algal blooms during which algae become so numerous that they discolour coastal waters “red tide”.

The algal bloom may also deplete oxygen in the waters or release toxins that may cause illness in humans and other animals.

You can see this phenomenon in the Gulf of Mexico, Florida, Northern California, Hong Kong, Australia but till then, scroll down and take a look how it looks on photographs.

• Aurora Borealis
• Two headed animals you haven’t seen
• Insects and nature are made one for another

The phenomenon in animal world of having more than one head is called Polycephaly.

This phenomenon arises from the same process as conjoined twins from monozygotic twin embryos.

Multi-headed animals are also symbol in mythology, though no such animal is known to have ever existed. Now, let’s take a look at these two headed animals you haven’t seen before.

• Animals you’ve never heard of
• Benefits of having a parrot at home
• Animals who can pretend they are dead

Cave in New Zealand hides a secret that does not exist anywhere else on the planet.

In the depths of limestone caves of New Zealand settled a colony of special fireflies. They emit a soft blue-green light, enough to illuminate the cave walls. These little creatures are called Arachnocampa luminosa. Here are photos of this phenomenon made by Joseph Michael.

• Blue caves
• 15 The most adorable caves
• Natural phenomena that are breathtaking