My backyard is full of these needle like stickers that attach to clothing skin and my dog. I need to know what they are and how to get rid of them. My poor long haired dog can't go out back until they are gone! Thank you!

Agh422. It is quite likely that you have Bidens (aka 'Spanish Needle') in your yard. The seeds are like small needles and will find their way into your shoes, socks, clothes etc. Nothing for it but to eradicate it, or keep it religiously deadheaded.

Spanish Needles (Bidens pilosa)

Spanish Needles, aka Common Bidens, a pretty weed with white flowers/yellow centers that attracts butterflies. Yes, the seeds stick tenaciously to everything! You need to eradicate the weed in your yard/area if you can, or at least cut it down before it makes seeds if you like the flowers. Btw, when you're pulling it, be SURE to get it out all the way to the roots. It breaks easily, and any base, or even a stem will jump right up again. Once the rains stop, or you stop watering it will pretty much stop growing, but it will come back next year with a vengeance, until you pull it all before it sets seeds.

Get a fine slicker brush for your dog, and brush them out religiously, because they are the kind of thing that work their way in and can cause skin lesions on a pet. (I have a long-haired cat) I recently hired a young person and tasked them with getting rid of all the Spanish needles, but she hasn't made too much inroads on it yet. Had no trouble finding bushels of them in the front yard. Here's a shot showing the flower, leaves and seeds with their little grabber ends all ready to pounce.

Looks like Bidens seeds to me too. My neighborhood has been overrun with Bidens pilosa this year and I've been yanking it out whenever I see it. I cleaned out two flower beds a few weeks ago that were covered in the stuff and my next door neighbor has it all over his property so I know it well be back on mine again too. By the time the plants are 12 to 18 inches tall they become harder to pull and have to be dug out because of the strong tap root. The flowers are pretty and they do provide nectar for bees and butterflies but here in Florida it can become a pest plant. I hate it when I'm working outside and my clothes and shoes and hair are covered with those danged seeds. Our Golden Retriever gets them in his fur too and it's a chore to brush them out!

with Bidens.

This plant is about the only one I am truly sorry that I introduced into my small garden. Yes, it is good for bees, both native and the honey bees, but the trade off is just not worth the pain. The seeds can bore through socks, sweatshirts, ouch! And the poor dogs! This plant is best left in a huge field where no one and their dogs will ever roam. It took 3 years but hopefully I have eradicated it from my yard.

Unfortunately, seeds are also dispersed with the wind.