Biodegradable bb pellets will Disintegrate after some time in your garden or the site you are playing on and are normally non-toxic and safe if your pet eats them, but please check the label if you buy some. generally, Biodegradable bb pellets will cost a little extra than their nonBiodegradable counterparts. one other thing to consider is that they break easier on impact so if you're shooting at someone who has a mesh mask on they can break and fragments could go through the masks mesh. some skirmish sites (in woods) and some countries (like holland) only allow you to use Biodegradable bb pellets so they may be your only choice. all things considered, they are probably the best bbs to buy if your shooting in your garden as you won't have to bother to pick them up if they annoy you. Need more info? Click here to see our BB Pellet Buying Guide.