Canadian bed bug infestations have increased as much as 600 per cent in the past decade.

The small, flat insects, which feed on human blood, have been re-appearing in hotels, hostels, shelters, public housing and private homes across the country.

Bed bugs were all but wiped out after the Second World War thanks to strong pesticides.

But they have been crawling back into beds across the country due, in part, to international travel.

People have been carrying the pests into Canada in clothing and luggage.

Another contributing factor is the decreasing use of strong pesticides and broad-based spraying methods for pest control.

Bites can lead to serious infection in some cases. However, health officials consider the bugs a nuisance, not a health hazard, because they're not known to transmit disease.

Entomologists say once the bugs make themselves at home, it can be difficult to send them packing.

Experts advise people to take precautions by vacuuming thoroughly, sealing cracks in walls and dry-cleaning or replacing pillows and washing all linens.