The Blues dropped points on their own turf in the Premier League on Wednesday night as relegation battlers Southampton came from behind to peg them to a 2-2 draw.
That result means Chelsea have won just one in six domestic matches at Stamford Bridge since Rafael Benitez took charge at the end of November.
Ba, who signed for the club from Newcastle earlier this month, knows Chelsea need to find a solution to their indifferent form on home soil.
"It's different when teams come here because they just want to defend and don't want to lose," he told Chelsea TV.
"When we go away, the opponents always look to take their chances and they think they can win at home. That's why the games are always more open when we play away, but at home we need to get back to winning ways.
"We had some good moments against Southampton, but some bad ones as well. They were lucky to only go in at half-time 2-0 down because it could have been more, but we need to finish all the chances we have and put the ball in the back of the net.
"At the end of the day, though, we conceded two goals, and went back home with only a point. Southampton came back and we let them believe they could get something from the game and they took their chance."
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