As standard /sitemap.xml is scraped. You can use the following to have multiple sitemaps
<?xml version="1.0" encoding="UTF-8"?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<sitemap>
<loc>http://www.exemple.com/sitemap1.xml.gz</loc>
</sitemap>
<sitemap>
<loc>http://www.exemple.com/sitemap2.xml.gz</loc>
</sitemap>
</sitemapindex>
You can also use your rrobots.txt to specify multiple sitemap xmls
Sitemap: http://www.example.com/sitemap-host1.xml
Sitemap: http://www.example.com/sitemap-host2.xml
See more here: Sitemaps.org Protocol