Hi,
Yes, you need to get them a larger cage and a better diet. That cage is much too small for even one bird, and millet should only be fed as an occasional treat in small amounts. Your birds are basically starving and suffering from malnutrition. They are scared because the cage is too small and they feel like they can’t get away from you. Parakeets are a prey species, so when your hand is too close, they think you are a predator trying to catch them. Since they can’t get away from you, their only option is to fight back. With two birds living together, you will never be able to tame them. They have each other as companions and have no incentive to be tame with people. I’m sorry to say this, but they are an exotic species driven by instinct, and in the wild, once they have a mate, they will not physically interact with other flock members. If you want a tame bird, you need a single bird, or you would have to separate these birds. But if these birds have bonded, and it sounds like they have, it’s not a good idea to separate them.
As for diet, you need to feed them a nutritionally balanced pelleted diet, along with some leafy greens, veggies and a small amount of fruit. You really should not feed any seeds.
I’ll give you the links to our feeding page, choosing a bird cage as well as our behavior & taming pages to help you understand how to feed & house them and what you can expect from them.
Bird Food Guide
Pet Bird and Parrot Behavior
Teaching Your Bird
Your Bird’s Home
Thank you for asking Lafeber,
Brenda