In the video, a person is seen holding their hand up to the glass of an aquarium. Inside the aquarium, there are several crabs of different sizes and colors. The crabs are crawling around on the rocks and gravel at the bottom of the tank. The person's hand is visible through the glass, and the crabs seem to be curious about it. The aquarium is well-lit, and the water is clear, allowing for a good view of the crabs and their movements.