What's to be made of the puzzling behavior of certain fur-bearing humans? What force compels them to leave their habitats to acquire their winter coverings? Is it instinct that guides them across state lines, and then back to the good neighborhoods where they live?

This unnatural phenomenon has puzzled some Maryland state officials who are concerned not with wildlife but with payment of taxes. Over the past few years, for example, a number of people who made purchases at Saks-Jandel, a furrier located in Maryland near the D.C. line, have had the wraps delivered to them at places other than their Maryland residences, thus avoiding Maryland's 5 percent "use" tax -- the equivalent of its sales tax.

That would be perfectly acceptable if they didn't then take the furs to their residences in Maryland. But state tax auditors who were routinely looking at Saks-Jandel's books began to suspect, given the large numbers of deliveries to places beyond Maryland's boundaries, that this was exactly what a number of the customers were doing. The result was that the state sought and got an agreement from the furrier to recover more than $100,000 in use taxes. The furrier, in turn, is trying to get some of that money back by asking approximately 700 customers to pay the taxes on deliveries they received outside Maryland.

A few months ago, authorities in New York were struck by the unusual distances jewelry was being sent to customers of the Fifth Avenue store of Cartier, Inc. An unusual plumage ritual involving travel across state lines? No. In that case, it was alleged in an indictment that store executives had advised customers they could avoid the state sales tax by having their purchases mailed to out-of-state addresses, and in some cases empty boxes were mailed to fake addresses while the customer left the store with the item, and without paying the tax.

In the case of Saks-Jandel, no such deception has been alleged. And now, says the lawyer for the store's owner, its sales people are even having to go to the opposite extreme of being "obtrusive and ridiculous" by asking customers where they will be wearing their furs.

As a spokesman for the Maryland state comptroller observed, migrations of the sort observed in this case are "not uncommon" in border areas where expensive merchandise is sold. There doesn't seem to be any way to monitor them other than audits and "obtrusive" questions from salesmen. Unless, of course, they'd like to follow the example of the ornithologists and band these birds.