Did your LO take to a pacifier right away or did it take a little patience and training?

I know ours likes it, when it falls out she'll root for it and when we actually successfully get it in, she sucks away and is soothed but she has a really hard time initially getting it in.

Any tips? We're using the Nuk orthodontic ones. We've also tried the gum drop and other more nipple-like styles and have had even less luck with them.