Packs of microwave popcorn have been recalled after a manufacturer discovered they could be infested with tiny pests.
The insects are 2 to 3mm long and dark brown, according to Rentokil.
Butterkist manufacturer Tangerine Confectionery stressed they do not pose a health risk.
The batch numbers of the multipacks affected are B8386, B8497 and B8496, and that of the single is A8394. These numbers are found on the best before panel on the packs.
A statement from the company said: "We would like to reassure customers that this does not represent any form of health risk and that the problem has been identified and is limited to only these two Butterkist products.
"Whilst the vast majority of Tangerine Confectionery products are made in our UK factories, the Microwave Popcorn is produced on our behalf in France and was available in Asda, Sainsbury's, Morrisons and other multiple and independent retailers between January 29 and March 13 2010."
Customers who bought packs with the relevant batch numbers should call 0800 0352535 for more information.
Those affected will be given a refund.