1.   Clinging to the sides of the chimneys were thick white mats of bacteria.

2.   In hot areas, you might welcome an aggressive grower like Jasminum polyanthum, which can form a thick mat on the pergola roof.

3.   Stepping gingerly across a thick mat of moss that has grown on the surface a Gardner pond, she snares a blue darner dragonfly in her net.

4.   The fish had been dining on pale morning duns in deep water at the very edge of a thick mat of bright green weed.

5.   The stream banks have been stabilized by grass and thick mats made of a biodegradable material.

6.   The worms apparently lived beneath a thick mat of single-celled organisms whose decaying bodies provided food while the mat itself gave them oxygen, Seilacher said.

7.   From the air, the thick mat of lush green water hyacinth that covers huge parts of Lake Victoria looks beautiful and harmless, even enticing.