1 month old chickens going into coop

A few minutes ago I was going to put my 1 month old chickens into their coop which is a 55 gallon plastic tote and thery were all in there. At what age will chickens go into there coop with out needing to put them in there by hand? If that's the case than I may consider getting another automatic chicken door

Close them in there for  a couple days with food and water. After that they should go in by themselves every evening.

I wouldn't expect chickens to voluntarily go into a "coop" that small.  They will much prefer a place where they can perch.

Its the brooder box that I started out with which was too small for 30 day olds. they ended up tramping each other when I put my hand in there. I lost 3 of them that way.

How many chickens are you talking about?  55 gal is very small.

Was 30, now its 20. This is my first time.

link to tote.
http://www.homedepot.com/p/HDX-55-Gal-Storage-Tote-in-Black-HDX55GONLINE-4/205597365?keyword=55+gallon+tote