Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
Cats and dogs can hear ultrasound.
350
Mosquitoes prefer certain blood types, and people with the “O” blood type are more likely to get bitten.
12
Meysi is one of the world's smallest dogs, measuring in at just 7cm tall, 12cm long, and weighing a meagre 250 grams (only slightly heavier than a hamster!)
11
The seahorse is the only fish to have a neck.
12
An average cat has 1-8 kittens per litter and can have 2-3 litters per year. During her productive life, one female cat could have more than 100 kittens. A single pair of cats and their kittens can produce as many as 420,000 kittens in just 7 years.
10