It is against the law to touch, feed, or otherwise harass seals. Harassment occurs when your behavior changes their behavior. If your presence causes any of the following reactions on land or in the water, then you are too close: Increased vocalizations by seals. Movement back into the water (single animal or the herd). All eyes are on you (single animal or several in the herd). Disturbance from normal resting position (lifting their head to watch you, stretching, waving foreflippers, yawning).

Seals, sea lions and walruses are currently placed in a sub-order, the Pinnipedia, of the Order Carnivora (which includes bears, dogs, racoons, weasels, hyenas cats, and mongooses). There are many recent studies on the genetic and fossil history of these groups and their place in the scheme of mammalian classification may well change in the near future. Three families of living pinnipeds are recognized, the Phocidae (hair seals or true seals), the Otaridae (fur seals and sea lions) and the Odobenidae (walrus). The term pinnipedia translates from Latin as "fin foot". All of these animals must come ashore to breed, give birth and nurse their young. Some species are at sea for several months at a time while others return to the shore every day.

It is absolutely normal for seals to be on land. Seals are semi-aquatic, which means they often spend a portion of each day on land. Seals need to haul out for a variety of reasons: to rest, give birth, and molt (annual shedding of old hair). Young seals may haul out on land for up to a week.

We don’t really know how seals navigate, but we do know that they are very good at finding their way while traveling at sea, in all types of weather conditions, day and night, while spending much of their time underwater. Recent improvements in tracking technology (satellite tracking, GPS tracking) has shown that seals can travel great distances and return to the same spots on shore with great precision. Grey seals can swim from Cape Cod to Nova Scotia in a matter of days.

Seal mothers and pups (as opposed to other pinnipeds) generally stay close together on shore and are not separated while nursing. Harbor seals are an exception, and mothers will leave pups on shore to feed offshore. Seal mothers and pups can stay in contact by sound. Harbor seal pups make distinctive calls that can be heard for up to a kilometer. When in close contact mothers and pups can identify each other by scent, recognizing scent from glands in the skin of their flippers and around their muzzles. If you see a harbor seal pup on shore, observe it from a distance and do not approach—its mother may be offshore. Seal pups are naturally attracted to moving objects that are bigger than they are. This can help a pup stay near its mother, but can also make a pup follow things that it shouldn’t (like you).

Seals see very well under water—better than they do in bright light above water. Their eyes are adapted with round lenses (like fish) and a large iris that fully opens underwater. On land the iris closes the pupil to a small pin point that lets the seal see clearly through the round lens. A seal’s eye is also adapted for low-light vision with a lining (similar to a cat’s eye) that reflects and amplifies the weak light at depth in the ocean.

Seals have many well developed whiskers, much like a cat. Like cats, they have a very acute sense of touch. Scientists think seals can use their whiskers to feel vibrations from swimming prey. Blind seals in the wild seem to be able to hunt and feed without sight.