For the same reason they use a soother (known as a dummy in the UK)
It soothes them.
Well a 9 month old baby may still need to suck his/her fingers. Babies suck on fingers and pacifiers for security. They somehow need it. If you want to get a baby to stop sucking his/her fingers, give him/her a pacifier to suck on instead. Or keep him/her occupied so whenever he/she sucks on her fingers, give him/her a toy to play with.
That is how babies eat.
TEN fingers
Pacifiers
Pacifiers
of course they do
Babies mostly do
suck my babies
We both suck our thumbs when we are babies
because of the peewie babies, u suck
it does suck, sims only have babies on pc,so that why i switched from ps2,
Suck on her fingers gently, squeeze her breasts and butt, and then suck her fingers a little more, also could try kissing her on her neck, down her body etc.