It relates to life in its entirety. Puppy dogs' eyes open days after birth. Vegetarians have small teeth to chew vegetables. Meat-eaters have large teeth to grab, rip and chew meat. Dogs, cats and lions must carry prey with their teeth.
Nails also distinguish vegetarians and meat-eaters.
Vegetarians have small nails, whereas meat-eater animals have big, sharp claws to tear their prey. Vegetarians have long intestines. They eat fibrous vegetables. This kind of food is digested quickly, but meat residues remain there for seven and more days. Meat-eaters have short intestines.