BANGKOK, Sept 28 — Bangkok residents have had plenty to contend with as floodwaters swallowed roads and homes after days of torrential rain, but for some, the biggest surprise came scurrying, crawling and scrambling out of the water.

Videos and photographs shared widely online during the floods showed cockroaches and other creepy-crawlies appearing in homes and flooded areas as residents sought higher ground.

Among those documenting the unwelcome visitors was actor and content creator Martin Bravo, who shared footage of his experience with companions as floodwaters inundated parts of Bangkok.

The videos showed the group dealing with the flood while keeping an eye out for insects and other creatures seeking refuge from the rising water.

The scenes came as Bangkok endured almost 48 hours of continuous rain, with accumulated rainfall approaching 300mm in some areas and all 50 districts eventually declared flood disaster zones.

The Bangkok Metropolitan Administration said more than 330mm of rain fell in some parts of the capital between Thursday and Sunday, while thousands of residents were evacuated as homes and roads were inundated.

For residents already wading through murky floodwater, the appearance of cockroaches was an unpleasant but predictable side effect.

Flooding can force cockroaches out of drains and sewer systems as rising water leaves them searching for dry shelter, according to pest-control guidance in Thailand.

Heavy rain can also drive other creatures, including centipedes and scorpions, from their usual hiding places into homes and other sheltered areas.

That helps explain why social media filled with videos of insects and other pests appearing during the Bangkok floods, adding another layer of discomfort to a disaster that has already forced thousands from their homes.

The floods affected about 52,000 households and sent nearly 4,900 people to shelters, according to the Bangkok Metropolitan Administration.

And while the cockroaches may have been looking for somewhere dry, Bangkok residents were left with the rather unpleasant task of deciding who should get there first.