|
|
Although the Roman numeral for the number 4 has always been taught to have been "IV," according to historians, the ancient Romans probably used "IIII" most of the time. This is partially backed up by the fact that early grandfather clocks displayed IIII for the number 4 instead of IV. Early clockmakers apparently thought that the IIII balanced out the VIII (used for the number 8) on the clock face and that it just looked better.
Vampire bats have a natural anticoagulant in their saliva that permits continuous bleeding after they painlessly open a wound with their incisors. This capillary blood does not cause any significant blood loss to their victims.
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
It is difficult to obtain enough calcium without consuming milk or other dairy foods.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.