By what age do babies generally develop full sensitivity for taste?

Well tastbuds for babies are there at birth but not until the baby is 5 months old that the baby starts reacting to salty foods, 3 months and the baby's tongue has grown thats normally when the baby starts putting things in their mouth 6 months you should start feeding the child solid food and thats when the taste buds fully develop however your taste buds change every 7 years

Because without physical activity, the body has extra "energy" if you will, and so when it is time for bed you are not tired, so you end up staying up all night. also there is probably an effect on your internal clock, which messes with your melatonin production which goes hand in hand with your sleep cycle