Retics in my experience are a bit more territorial than the burms you have worked with in the past. They also have a tremendous feeding response. Differentiating between the two behaviors is something that you will need to be mindful of as you "learn" your snakes.
I'm sure you've looked back through some of the older posts. As Marcia suggested and am sure Brian would agree the importance of developing a routine to let the snakes know when it is NOT feeding time. For example, if something dead and furry falls in the cage it is feeding time. If a hook comes in the cage follwed by a few pats on the side it is NOT time to eat.
The territorial side is what I think throws some new to retics for a loop. You get your new snake home, let it get settled into it's new surroundings, reach in to pull it out and, WHAM!! you get nailed. What happened to the nice snake you were handling at the show/store? It's the same snake. There is a very good chance that if you would take the snake out of the cage it would clam right down and you could handle it freely. I'm sure you've seen ads for retics that read, "fine once out of it's cage" this happens to be true more often than not.
Fortunately your snakes are not too big yet. If you take then out and handle then freely, which will probably be a little scary at first, you can start building some trust in them. OVER TIME, the snakes will start to "learn" the routine and should not respond by striking as often, if at all.
One last piece to remember before I end this rambling post. When working with retics as they get larger, always be focused on what you are doing. Don't operate from a standpoint of fear , but rather caution and awareness. I've handled some big girls out of their cages for exercise, cleaning, or whatever, without incident, totally relaxed. I put them back in their cage, closed the doors, turned around only to hear a solid THUD as she struck the glass behind me.
These are beatiful, intelligent animals that are rewarding to work with. They are not, however, for the feint of heart.
Good luck, glad to have you here,
Josh.