Location: A clear open space where running is possible

Resources: Set of camouflage crab cards – Each set should contain 50 or more crab cards of equal size, half printed on dull card, greys, browns and olive greens (dappled, dull patterns work well) and half on bright colours (Florescent card works well). Cards can be laminated to make them last. A page of crabs is supplied to photocopy. Use cones, rope or sticks to mark game area.

Running the Game:

An area approximately 10mX10m is marked out. Spread crabs evenly in this area, partly buried so they don’t blow away but with most of the card visible. Make a starting line 10m away from this zone. Clear the whole area of large obstacles to make safe for running. The group is split into 2-6 similarly sized teams.

Explain that crabs are common shore species and that fish like bass prey on them. They will be teams of bass looking for crabs to eat. Like a relay race, the first person from each team runs to the crab zone and brings back 1 crab at a time. When they return, they put the crab in a pile next to their team, go to the back of the line and the next person goes and so on.

When half of the crabs have gone, stop the game and ask each group to count the number of brightly coloured crabs and the number of dull crabs they have. Overall the bass should have more brightly coloured crabs than dull ones. Explain that they have just taken part in an experiment to find out what colours are best camouflaged on a sandy beach and that there are equal numbers of each type. If the results are not as expected discuss why this may be. Talk about camouflage and colouration. Continue the game until all the crabs are gone. The team with the most crabs wins.



Group Size

10 or more


5-15 mins

Ocean Literacy Links