Finding the products you need when you need them can be difficult right now. It’s also a bit of a nightmare for retailers, who are trying to stock up ahead of the holidays.

The rush to fill shelves is responsible, in part, for a 15% rise in imports from China last month.

In normal times, retailers do not want to store products for very long. When you have a lot of inventory, you’re tying up your cash and you have to pay for more warehouse space.

“Anytime you’re storing product, it gets damaged, it gets misplaced,” said David Marcotte, a senior vice president at Kantar. He said that, right now, retailers are ordering whatever they can well in advance “because sincerely they just don’t know when and where it’s going to show up.”

Global supply chains are a mess. There are shortages of raw materials and computer chips and COVID outbreak can shut down factories at a moment’s notice. Not to mention the backups at ports.

Cargo ships are often just sitting there, said James Zahn at the Toy Book, a trade publication for the toy industry.

“Where some companies might have had three weeks of having their product on the water, now it’s over a month and in some cases two months.”

So, retailers are looking for alternatives — products they know they can get their hands on. The Toy Book just put together a list of toys that are lying around in U.S. warehouses, including puzzles, board games and paint-by-number kits, which can be shipped quickly when a retailer needs something to put on shelves.

Retailers are also looking at what they have and “marketing the products where you have the deepest inventory,” said Chris Considine at the consulting firm AlixPartners. “I’ve been on calls [in the] last few weeks for clients who are specifically doing that.”

In other words, if retailers have a lot of puzzles, they are going to try their hardest to sell you those puzzles.