Five-time Wimbledon champion Venus Williams recovered from a first set setback to beat Romanian qualifer Alexandra Dulgheru 4-6, 6-0, 6-1 in just under two hours.
Roger Federer just breezed into the third round of the 2018 Wimbledon Championships.
The second seed complained about the nuisance the ants were causing and perhaps suffered as a result because she lost to Russia's Ekaterina Makarova 4-6, 6-1, 5-7.
With Federer having an elegant answer to everything Lacko could throw at him, it was not until the 20-times Grand Slam champion walked off court that he was finally stumped.
Williams is back at Wimbledon for the first time since giving birth to Alexis Olympia in September.
And Federer looks well placed to contend again this year after a sublime second-round defeat of Lukas Lacko on Wednesday, following which he explained how he has been able to stay at the very top of the game.
They were treated to the Swiss' full repertoire, with Federer saying after his victory that playing the percentage shots too much "becomes boring".
Lacko had probably hoped he could throw some curve balls Federer's way after enjoying a run to the Eastbourne final at the weekend.
He won 93 per cent of points won on his first serve, winning all of them in the second and third sets. Novak, ranked 171, converted six out of 11 break points en route to victory in almost three hours.
Federer was set to play Jan-Lennard Struff of Germany and Williams faced Kristina Mladenovic of France as they continue their quests for a ninth and eighth Wimbledon title, respectively.
After her loss Swan said on Twitter: "Tough one today but overall a great experience".
The first set was over in 24 minutes. "I felt good out there and had less nerves than in the first round", he told BBC Sport.
"I'm getting there, I'm not there yet but I expect to get there not only for Wimbledon but for tournaments in the future".
Seven-time champion Serena Williams faced little resistance in her progress to the third round as she overpowered Bulgarian qualifier Viktoriya Tomova 6-1, 6-4.
Struff, coming off of a tiring 5 setter against Ivo Karlovic which stretched to 13-11 in the decider, will have to bring his A-game to pose a threat to Federer, who seems to be on track to defend his 8th Wimbledon title.
French star Gael Monfils got caught up in the excitement and drama of England's World Cup victory over Colombia while watching the penalty shootout in a London pub.
Daria Gavrilova eased past Australian compatriot Samantha Stosur 6-4 6-1 in 81 minutes to reach the third round at a major for just the fourth time in her career.
"I was actually into it at the end".