Egg producers blame the ongoing bird flu outbreak for driving prices up to record highs. But some believe giant companies are taking advantage of their market dominance to profit handsomely at the expense of egg buyers.

Soaring egg prices have consumers boiling, and on Wednesday, the United States Department of Agriculture blamed rising costs on the bird flu epidemic and said it will take new steps to quell the outbreak.

The nation’s biggest egg producer has seen rising revenues and profits. Now some Democrats are calling for an investigation into pricing practices in the industry.