because they smell
Yes it is. Only a tiny, tiny, tiny bit though. But more so for dogs... It contains caffeine and theobromine, both of which are listed carcinogens by the IARC, part of the World Health Organisation.
Listing them all would be time-consuming so lets put it this way. Drugs can cause a pupil to change in two ways by dilation making the pupil larger or constricting the pupils. Only two drugs constrict the pupils those being opiates and alcohol. So anything but, these can cause the pupils to dilate.
Optic nerves can make eye pupils be big all the time. If the eye doctor told you this then it is correct.
You are confused. They DO have pupils. All animals have pupils. Pupils are the black part from which you see through. But hamsters are small animals that live underground in little caves, so their pupils need to be bigger so they can see better in the dark. You are probably asking why they don't have the white part of their eyes, but they actually do. It's behind their eyelids, and the edges of it is brown, and then turns into off-white, so it's hard to see. If you stretch the piece of skin (softly) that they have in between their two eyes on the forehead, you can pull the eyelids up so you can see the white part. *** They are NOT nocturnal. Or diurnal. They are awake at all times, but take a few one-hour naps throughout the day, so they are always active.
All dogs are Canis lupus familiaris, so all dogs are in the genus Canis.
What do you mean by "it" and if "it" is poo ALL dogs do "it" then so your question is half finished
When light come into your eye your pupils will get smaller. In a dim or dark room your pupils will enlarge to let in more light so you can see. Also some drugs will make your pupils smaller, or when your high they dilate.
All species of tetra have very tiny mouths so the bite would be very tiny.
Cuteness is in the eye of the beholder. Teacup dogs are a bit smaller; while toy dogs are only slightly larger. I think at some point tiny dogs begin to look like other critters. So I'm partial to toy on this one...but this is purely an opinion question.
I really doubt that there is anyone examining the size of your pupils before allowing you to step onto the ice. If you were ice skating at night, you would have naturally dilated pupils. So yes, you can skate with dilated pupils.
it is mostly impossibel to see a flea in a dog because it is so tiny that you can't even see it.
No nothing is wrong with your cat, her pupils are wide because when any object with eyes looks at a bright light, their eyes get small. But when it's dark, the pupils get big. So know you know why. :)