Gauze. Gauze is the BEST thing to have when you think you should intervene. It is suggested not to ever help chicks out but under certain circumstances (like hatching call ducks) help may be needed. You should always ask the BYC members for advice first. But back to the point, a lot of times when helping you may injure the delicate veins on the membrane, causing a little bit of bleeding. It may be only a drop or two of blood, but for the chick it is like a pint of blood. Many people think that when chicks die after they help is because they were just weak chicks. But when a chick looses even a little bit of blood it can be fatal for the chick. You should always have gauze on hand when hatching chicks and if you need to help and happen to notice blood, apply the gauze. It has saved my chicks so many times. Also make sure that you wet (I use wet Q-tips) the membrane so you can see the veins. NEVER CUT A VEIN if you can help it. If you help the chick out and it still has yolk, carefully put it back in the shell and make sure the yolk doesn't dry! I have noticed that sometimes chicks have a hard time hatching when they are in a carton, so if a chick is having trouble take it out of the carton. When helping it may be a good idea to chip away the shell the same way a chick would, by zipping all the way around, when you do this you DON'T have to break the membrane, just chip away the shell. You can tell if a chick is ready if all the veins are clear or have little blood in them
As you can see in the picture this chick was very ready, yolk absorbed, blood absorbed. The string attached to the shell and the chick is actually a vein that has no more blood in it, the chick should break free from it when it starts struggling to move around.

Here is another pic of a chick that wasn't ready. you can see red veins and the yolk not fully absorbed.

As you can see in the picture this chick was very ready, yolk absorbed, blood absorbed. The string attached to the shell and the chick is actually a vein that has no more blood in it, the chick should break free from it when it starts struggling to move around.
Here is another pic of a chick that wasn't ready. you can see red veins and the yolk not fully absorbed.