Sotheby’s New York City headquarters is reportedly experiencing an infestation of mice. According to the New York Post, the mice arrived courtesy of some unidentified items in Sotheby’s 1,500-lot sale of Rachel “Bunny” Mellon’s estate.

That series of sales, which concluded on November 23rd, brought in a whopping $218 million, more than double its $100 million presale estimate (see “Bunny Mellon Collection More Than Doubles Expectations at $218 Million“). Over 98 percent of the lots sold, and 85 percent of those went for more than their high estimate. The sale was led by a pair of Rothkos, which went for $36.5 million and $40 million, as well as a 9.75 carat blue diamond that set a new record at $32.6 million.

The total will no doubt have paid for an illustrious troupe of exterminators to come root out the mice before they chewed away at some eight-figure art. But the fact that such an infestation could have occurred in the first place is surprising.

The Post speculates that the rodents could have snuck into Sotheby’s HQ in some of the more miscellaneous items in the sale: linens, baskets, and furnishings that hadn’t been restored before hitting the auction block. Bunny Mellon died in March and the items for sale were sourced from five different residences—some of which she had presumably not visited in some time—giving the mice plenty of time to nest.