A two-year-old was pushed to the ground and sustained a bump to the head during an aggravated burglary.
A man was also punched in the face and a woman threatened with a knife during the incident that happened at around 8pm on Monday, December 16 at a home on Central Drive, Rossington.
Two men knocked on the front door and were told by the occupants to go to the back door.
One man is alleged to have entered the address and assaulted a male occupant by punching him before threatening a female occupant with a knife and demanding money.
A struggle took place during which a two-year-old child was pushed to the ground, causing a bump to her forehead.
The man left the premises without money but is believed to have taken the back door key as he left.
The man is described as white, aged 25-30 years old, over 6ft tall with slim, wiry build. He is believed to have distinctive teeth; his front teeth were black, worn away or missing completely.
A second male was not seen.
Anyone with information is urged to contact South Yorkshire Police on 101 quoting incident number 1208 of 16/12/13 or call Crimestoppers anonymously on 0800 555 111.