Super Z Outlet Safari Party Hats Plastic Jungle Theme Animals Explorer Pith Halloween Costume Toy for Kids

Q: Do these hats stay on?

The hats are flimsy, they would stay on a kids head while they are sitting still...lol These are better used for decorations that's what I ended up using mine for.

Q: Are these hats too big for 4 year olds?

No I bought them for my 2 year olds birthday in January and I had kids ages 1-13years old wearing them

Q: Will this hat fit an adult

Yes, it did for the ones that we purchased it for. The dimensions inside the hat are 6 inches wide (ear to ear) and 7 inches long (front to back). Hope this helps!