How do I stop hard biting?

Any ideas for treats for training or how to bond with a pair who are bonded to each other? So I have posted a few months ago, I purchased 2 quakers (fem) from a pet store back in November. I had visited the store for 2 months before bringing them home. For a while they wanted NOTHNG to do with me. Gradually, they started coming down if I would sit on the floor and hop on me and investigate me. I thought I was making progress but now they are going backward and are EXTREMELY cage aggressive, even if I am putting in food or trying to open the top to let them out. I don't think it's fear, because if they are out and I am sitting at my desk, sometimes they will sit behind me on their cage door. They will walk all around me when I am sitting on the floor, without even a second glance. I have watched every youtube video, read articles, am in facebook groups, to find ideas on how to stop the biting. I have tried ignoring it (only happens again) yelling ouch and turning my back and/or leaving the room. I tried standing next to the cage with my hands hidden, which they seemed interested and would come and explore my clothing and freckles. Lucy then hopped on my shoulder, lightly pulling my hair, then bit me really hard in the cheek for no reason. I hope I don't sound selfish, but I didn't get birds so that I could just feed, water, and buy them lots of toys, I want to be able to interact and have a relationship with them. I have also tried target training, but they literally won't take any treat I offer. They grab it and immediately drop it, which makes training near impossible. So unless I can get some other ideas, my next step is to either have them sleep in a small cage at night to help them be less aggressive of the big one, or to separate them when they are not out. I know they are very bonded and have been together since birth. I do realize the time of year it is, and they just turned 1, but I am just starting to get really discouraged and feel like giving up.

Most parrots enjoy bits of almonds or walnuts as treats. I've used plain Cheerios and unsweetened wheat or rice "chex" type cereal blocks. Most of mine also enjoy plain oatmeal, served at room temperature.

A consequence of bonded pairs is they may or may not desire a relationship with their parront. I agree they don't seem afraid of you, rather uninterested. At one year of age, they may be on the verge or undergoing puberty, certain to confuse the issue.

Though I am not familiar with Quakers, typical efforts to bond might be successful. Helpful tips here: http://www.parrotforums.com/general-parrot-information/49144-tips-bonding-building-trust.html

Bite Pressure training and Clicker/Target threads:
http://www.parrotforums.com/training/63988-bite-pressure-training.html
http://www.parrotforums.com/training/60435-clicker-target-training.html

I wouldn't allow them to sit on your shoulder until they can be handled safely. Mine will occassionaly bite me really hard for no reason even when it seems like they're just interested in preening you all of a sudden and literally last minute while i was typing she nipped me on the cheek (she's on time out). Normally this is due to them wanting something/not wanting something or just showing displeasure in something i think. Not like they can use their words So if they're comfortable being near you to the point of jumping on your shoulder, just go with target training.

Reason turning your back on them won't help in my opinion is that normally that type of response is mean't to remove your attention, quakers are quite attention needy. So if they do something bad, you leaving sucks for them because hey, my buddy is gone. But they already have the interaction of each other, a bond, and so might just view you as a third wheel. I think keeping them in seperate cages will help here.

This way you can let each one out and work with them independently of the other with basic target training. I can't stress enough that stick/clicker training is an amazing way to bond with your bird while being able to teach them fun little tricks. Voice commands are really helpful because you can eventually change behaviour in an instant (ideally) and distract them away from bad behaviours without negative impacts on the bird. However, if they have each other to play with, it will be a much tougher battle earning their trust.

Again, I think the main issue though, is that you're unfortunately third wheel while these two are shacked up together. Also you'll want to (if you haven't) get a mix of treats and try them one at a time. Pinenuts are really good but i think they're quite fatty, i've switched from pine nuts to sunflower seeds/veggies i don't normally include in their fresh veggie mix. They do sell little pots of assorted bird treats and you can pick them out one at a time. You might find that each one has their own favourite.

Hope this helps, and i'm no means an expert. I'm just trying to imagine this from the "shoes" of a quaker best of luck and believe me they will be worth the effort. Mine is hillarious, as well as a bit of a hell raiser at times but always makes me laugh a few times a day with her character.

also how long have you had them for?

Oh also, i think training/bonding should probably happen away from the other, preferably in a seperate room out of site of the other. This might be difficult if they're flighted, but if they aren't it will be much easier. May also consider having them caged in seperate rooms until you've formed a bond with both of them. This could take maybe a couple of weeks or a month, but it wouldn't be fair for anyone to tell you just how long it will take to break a bond, and then form one with each bird.

Quakers are notorious for being cage aggressive, highly so. I suggest doing any training separately, and away for the cage, in another room with the cage out of sight if possible.
Patience! Quakers are also noted as one of the stubbornest parrots out there.