We are all females in the very first few weeks before birth (the "male" Y chromosome activates later than X.) Submitted by: Anuj - Gorakhpur, India
The world's smallest fish is Paedocypris progenetica (7.9 mm long) found in Indonesia.sciensational.com Submitted by: Antonia - Brazil
The female rattlesnake hatches eggs inside her body, and baby snakes emerge active with no shell (called a viviparous birth.) Submitted by: Manu - Agra, India
Our tongue is the only muscular organ that is not attached to the skeleton, and works independently. 
The tallest known living tree is Hyperion (a Sequoia sempervirens redwood at 115.85 m) in California, USA. Submitted by: SinisterBlade_9
The fungi are neither plants nor animals but a life form of their own. Submitted by: Manit - Mumbai, India
Coyotes actually run much faster than Road Runners (70 km/h vs 40 km/h), unlike the cartoons.sciensational.com 
A dragonfly's eye has over 30,000 separate lenses (human eye has one.) Submitted by: Robbie Francis D. De Jesus - Philippines
The mistletoe plant is actually a parasite on its host tree. Submitted by: Rodrigo - Los Angeles, United States
Cornea is the only part of the body which takes oxygen directly from the air. Submitted by: Bohemia - Amritsar, India
Octopuses and squids (cephalopods) have followed an evolutionary path completely different from other animals. Submitted by: Nicole Chelseame
We are taller in the morning and shorter in the evening (~1-2cm due to spine compression.)sciensational.com Submitted by: Aashita - Mumbai, India
Women's bodies have less water than men's. (45-60% vs 50-65% respectively.) 
The largest muscle in the human body is the buttocks (gluteus maximus.) Submitted by: Cedaneice - Davo City, Philippines
Birds are actually theropod dinosaurs, thus being the only direct descendents of dinosaurs living today. Submitted by: Vaan - Nepal
Even a 270 kg (600 lb) Octopus can squeeze through a small coin-size hole. Submitted by: Madhuri - India
Most of us have harmless microscopic mites (Demodex) living in our eyebrows.sciensational.com Submitted by: Nirvisha - Portage, Indiana, United States
The largest organ of the human body is the skin. Submitted by: Ton - Philippines
The lizard Tuatara has a third eye for ultraviolet light (called a parietal eye.) Submitted by: Madhuri - India
The biggest seed in the world is the Coco de mer (weighing up to 18 kg.) Submitted by: Alyssa Michelle de Lemos - Philippines