You can try to offer them whatever you like, but ultimately getting them eating is the most important thing. I find it is easier to get them started with mouse hoppers because they are smaller so less intimidating. They are much more animated (more movement) which tends to create a stronger predatory response in the hatchlings. They also have more fur than rat crawlers which probably means more scent so a little stronger target. Once they are eating regularly getting them to switch to rat crawlers is usually not a problem. Congrats again. It looks like a pretty nice clutch.