Environment

6. a night animal who flies
8. vehicles moving on a public highway
9. (of a species) seriously at risk of extinction
10. the presence in or introduction into the environment of a substance which has harmful or poisonous effects
12. an orange animal, who makes a sound similar to a dog
13. a small insect who sucks blood

1. to make something less
2. a distinct compound or substance, especially one which has been artificially prepared or purified
3. to be careful
4. a piece of ground adjoining a house, in which grass, flowers, and shrubs may be grown
5. a sound, especially one that is loud or unpleasant or that causes disturbance
7. snakes, lizards, crocodiles, turtles, and tortoises
10. consisting venom
11. a large area of water surrounded by land