Why would taking care of a ferret be more challenging than taking care of a dog?

I've had a couple dogs in my life and know that they are a big responsibility, so ferrets would be just as big as responsibility.

Ferret's have to go to exotic vets, they need more attention then a dog or cat, take a little longer to potty train and stop chewing, need to be cleaned up after more often because the make more messes and get stinky more often the cats and dogs. However they are very lovable, fun to play with and watch. I had one for 5 years and she passed away from a tumor in her spleen. Which is also common thing ferrets get because of bad breeding. If you thinking of getting one do your research and don't buy from pet stores or petsmart. Most ferrets from those places come from ferret farms (poor breeding and conditions) try animal shelters or craiglist for some that need theirs to be adopted.

they get more into things even thought some cant see. I think it would be harder. They dont listen

Ferrets are harder than dogs because you have to spend at least 4-6 hours outside of the cage with your ferret. They need high quality, expensive food, expensive supplies, and expensive housing. They are just an expensive pet. They are harder to litter train as they are never 100% litter box trained and stopping their biting habit is a very tough process which requires persistence! I have had ferrets and dogs and I personally think ferrets are not necessarily "harder", but more challenging than dogs.