The supply chain squeeze is showing up in the infant formula grocery aisle. Some parents across the U.S. are finding empty shelves when they go to buy infant formula. And that can cause a lot of stress, said Clara Cooper with the Houston nonprofit LIFE.

“When you go to the grocery store, you find out that there’s a shortage, that mom or dad or that guardian has to ask that question, ‘How am I going to adequately and properly feed my baby?’” said Cooper.

Adults can, say, skip the burgers and go for a salad if ground beef is sold out. But you can’t do that for babies. And some infants with sensitive tummies need specific brands.

“Infant formula is an incredibly complex product,” said Brian Dittmeier with the National WIC Association.

He said some infant formula is manufactured abroad, and some brands are made in the U.S. — so there’s not one reason for shortages. 

“Sometimes formula is shipped on container ships, sometimes it’s driven on trucks,” said Dittmeier.

These are all forms of transportation which are slower these days. If parents can’t find formula at one store, Dittmeier said they should try another. It may be that store just hasn’t gotten the delivery yet.