We have recently, mid sum... - Ask Extension
We have recently, mid summer through fall, seen an influx of small red and black spiders inside our home, mostly in the kitchen and near the exterior ...
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We have recently, mid sum... #159243
Asked November 02, 2013, 12:15 AM EDT
We have recently, mid summer through fall, seen an influx of small red and black spiders inside our home, mostly in the kitchen and near the exterior doors. They are usually on surfaces and do not seem to make webs. We find about 1 a day on average. They are about 1 cm head to thorax, with dark red-to-black abdomen and chalky gray thorax and red legs. A photo is attached. Our house is kept clean professionally and we have not noticed any other insects inside (other than crickets in the basement). Our dog wears Advantix and is an inside dog. With a 6 month old baby in the house is this type of spider something we should be concerned about? Is a professional exterminator likely to be helpful or ineffective. Thanks for your advice and help.
Prince George's County Maryland
Expert Response
The spiders you have found are likely Sac Spiders, possibly the Broad-Faced Sac Spider, Trachelas tranquillus. It is not uncommon for these spiders to enter homes in autumn, likely in search of warmer, drier habitats.
We have observed much larger spider populations this year which probably resulted from the rainy spring and early summer. These weather conditions prompted larger populations of other insects which spiders feed upon. The sac spiders feed on dead spiders and dead insects, which make them valuable scavengers, but also presents another minor consideration. It is best to avoid contacting these spiders since they will bite in self defense and because of their peculiar dietary habits their bite may result in secondary infections. It would be appropriate that you keep an eye out for them and vacuum them up whenever you see them.
LS
We have observed much larger spider populations this year which probably resulted from the rainy spring and early summer. These weather conditions prompted larger populations of other insects which spiders feed upon. The sac spiders feed on dead spiders and dead insects, which make them valuable scavengers, but also presents another minor consideration. It is best to avoid contacting these spiders since they will bite in self defense and because of their peculiar dietary habits their bite may result in secondary infections. It would be appropriate that you keep an eye out for them and vacuum them up whenever you see them.
LS
