An apiarist says swarms of bees landing on cars in Adelaide were simply resting after gorging themselves on nectar before taking flight to create a new hive.

Key points: Bee swarms will travel once their hive is overcrowded and travel 200–300 metres before resting

Bee swarms will travel once their hive is overcrowded and travel 200–300 metres before resting Spring is the time of year that bees are more active

Spring is the time of year that bees are more active Bees are likely to be attracted to bright colours

Thousands of bees landed on a car parked at the Westfield Marion Shopping Centre on Wednesday and had to be coaxed away by a beekeeper.

Another swarm took a break on a car parked at Christies Beach on Tuesday.

South Australian Apiarists Association president Josh Kennett said it was probably attracted by the Hyundai's yellow paint job.

"They'll attach to those colours … it seems to be light colours, but those swarms will probably head to those places they like," Mr Kennett said.

Spring was also a cue for bees to get busy.

"It seems to be full on this time of year, I'm on a couple of Facebook pages and you see quite often there's people with swarms in their backyards and on fenceposts," Mr Kennett said.

A swarm of bees cover part of a Hyundai. ( Supplied: Rachel Frear )

He said a swarm took flight when a hive became overcrowded.

"Once that's full and they think they've got enough to survive, they'll send the old queen bee plus some of the bees out and they'll repopulate another spot and they'll start again," Mr Kennett said.

"They'll go 200 or 300 metres and they'll rest again and they'll keep looking until they find somewhere."

Mr Kennett said there were ways to deal with a swarm alighting on a car if you could not wait for a beekeeper.

"If you're in a bit of a hurry — if you're game enough, sweep them off into the gutter and then drive off," he said.

"Generally once they've landed on something like that they won't actually stay there.

"They're only resting for a while and then they'll send out the scouts which will find a better place for them to live.

Mr Kennett said if a swarm landed in a tree it would usually be gone by the morning and were generally not aggressive if left alone.