Mouse melon fails to thrive

I was so excited about my mouse melon and special-ordered seeds from a garden catalog.  I sowed them indoors about 3 weeks ago, but only three of the 9 seeds I planted came up. 

These tiny seedlings are supposed to be ready to go out this week, but they look so delicate and fragile, I don't have the courage to put them out--especially not with a rogue squirrel about!