Question: "When should I use a wiggle song?
Answer: "Whenever the children need it!
It is useful to remember that the children in Primary come in all abilities and all ages -- from 11 down to barely 3 years old. Sometimes the Seniors outnumber the Juniors or vice versa. The older children may be able to pay attention for longer stints, but remember that the little ones probably can't even read yet and to them EVERYTHING IS NEW and different. The last thing they can handle is more sitting still while people are just talking.
January is the beginning of a new year, and that, for most Wards, means a TIME CHANGE. After sitting in Sacrament Meeting for one hour, the children are likely going to be fidgety, especially the very young ones. The new schedule may be spanning lunch time or nap time, too, which complicates things. Younger children have a hard time adjusting to new rhythms in their day.
A few of my favorite "go to's" from the CSB are "My Hands" 273, "Oh, How We Love to Stand" 279, and "Hinges" 277. I usually sing them unaccompanied so I can vary the Tempo. I often go faster and slower in places or even put in complete stops. That way I am training the children to watch me for Tempo, Breathing, Facial Expressions, and Physical Movements - including any "freeze" pauses.
The key is to use a wiggle song or activity in quick, surgical strikes. A few seconds change of pace is all you need to provide relief and regain the children's attention. Then you can go back to teaching whatever you had planned.
Wiggle Songs are your FRIENDS!