Hippos:Whales of the Land

please give me some comments to improve my writing skills thank you

    Whiles the hippopotamus may look very gentle animal, it is actually quite dangerous. In fact, the hippo has killed more people than any other wild animal in the world! Their teeth are very sharp and can grow up to 125 centimeters long. Still most people need not worry since hippos are very vegetarians and only attack when they are threatened.

    The hippopotamus spend most of the day sleeping in the mud. During the night it wades in the water looking for food. The hippo is very comfortable in lakes and river and can actually spend up to minutes under water. Recent research suggests the hippo is more closely related to the whale than to land animals such as the elephant. Baby hippos are even born in the water and so learn to swim immediately. It's no wonder the word hippopotamus actually means " river horse." 

Reviews

[Vic]

This is a clear piece of writing. I would cut the word "very" before vegetarians and maybe you could include the number of minuets a hippo can spend underwater.