Mysterious Underwater Circles In 1995, there were found beautiful mysterious underwater circles in Japan. The origin of this at first was an enigma. The locals and the divers call it as “mystery circles” since no one knew how they were formed. Finally, the secret behind these circles revealed in 2011 when a male species of pufferfish was found as the creatures behind it. Further study showed these small pufferfish make the ornate circles to attract mates. Males laboriously flap their fins as they swim along the seafloor, resulting in disrupted sediment and amazing circular patterns. Although the fish are only about 12 centimeters (5 inches) long, the formations they make measure about 2 meters (7 feet) in diameter. When the circles are finished, females come to inspect them. From Hiroshi Kawase, the curator of the Coastal Branch of Natural History Museum and Institute in Chiba, Japan once it is know if they like what they see, they reproduce with the males. However nobody knows exactly what the females are looking for in these circles or what traits they find desirable. … females come to inspect them. The word 'them' in the text above refers to …

Question

Mysterious Underwater Circles

In 1995, there were found beautiful mysterious underwater circles in Japan. The origin of this at first was an enigma. The locals and the divers call it as “mystery circles” since no one knew how they were formed.

Finally, the secret behind these circles revealed in 2011 when a male species of pufferfish was found as the creatures behind it. Further study showed these small pufferfish make the ornate circles to attract mates. Males laboriously flap their fins as they swim along the seafloor, resulting in disrupted sediment and amazing circular patterns. Although the fish are only about 12 centimeters (5 inches) long, the formations they make measure about 2 meters (7 feet) in diameter.

When the circles are finished, females come to inspect them. From Hiroshi Kawase, the curator of the Coastal Branch of Natural History Museum and Institute in Chiba, Japan once it is know if they like what they see, they reproduce with the males. However nobody knows exactly what the females are looking for in these circles or what traits they find desirable.

… females come to inspect them.

The word 'them' in the text above refers to …